Botulinum toxin pharmaceutical compositions with multiple stabilizers

ABSTRACT

A botulinum toxin pharmaceutical formulation free of animal derived proteins, comprising a botulinum toxin and a recombinant albumin, suitable for therapeutic administration to a human patient, and methods for treating patients with various diseases and afflictions with the formulation.

CROSS REFERENCE

This application is a continuation in part of application Ser. No.10/047,058, filed Jan. 14, 2002, which is a continuation in part ofapplication Ser. No. 09/500,147, filed Feb. 8, 2000. The entire contentsof these prior patent applications are incorporated herein by reference.

BACKGROUND

The present invention relates to Clostridial toxin pharmaceuticalcompositions. In particular, the present invention relates to botulinumtoxin pharmaceutical compositions and uses thereof.

A pharmaceutical composition is a formulation which contains at leastone active ingredient (such as a Clostridial toxin) as well as, forexample, one or more excipients, buffers, carriers, stabilizers,preservatives and/or bulking agents, and is suitable for administrationto a patient to achieve a desired diagnostic result or therapeuticeffect. The pharmaceutical compositions disclosed herein havediagnostic, therapeutic and/or research utility in patients such ashumans, as well in, for example, canine, equine, bovine and porcinemammalian species patients, and in non-mammalian avian species patients.

For storage stability and convenience of handling, a pharmaceuticalcomposition can be formulated as a lyophilized (i.e. freeze dried) orvacuum dried powder which can be reconstituted with a suitable fluid,such as saline or water, prior to administration to a patient.Alternately, the pharmaceutical composition can be formulated as anaqueous solution or suspension. A pharmaceutical composition can containa proteinaceous active ingredient. Unfortunately, a protein activeingredient can be very difficult to stabilize (i.e. maintained in astate where loss of biological activity is minimized), resultingtherefore in a loss of protein and/or loss of protein activity duringthe formulation, reconstitution (if required) and during the period ofstorage prior to use of a protein containing pharmaceutical composition.

Stability problems can occur because of protein denaturation,degradation, dimerization, and/or polymerization. Various excipients,such as albumin and gelatin have been used with differing degrees ofsuccess to try and stabilize a protein active ingredient present in apharmaceutical composition. Additionally, cryoprotectants such asalcohols have been used to reduce protein denaturation under thefreezing conditions of lyophilization.

Albumin

Albumins are small, abundant plasma proteins. Human serum albumin has amolecular weight of about 69 kiloDaltons (kD) and has been used as anon-active ingredient in a pharmaceutical composition where it can serveas a bulk carrier and stabilizer of certain protein active ingredientspresent in a pharmaceutical composition.

The stabilization function of albumin in a pharmaceutical compositioncan be present both during the multi-step formulation of thepharmaceutical composition and upon the later reconstitution of theformulated pharmaceutical composition. Thus, stability can be impartedby albumin to a proteinaceous active ingredient in a pharmaceuticalcomposition by, for example, (1) reducing adhesion (commonly referred toas “stickiness”) of the protein active ingredient to surfaces, such asthe surfaces of laboratory glassware, vessels, to the vial in which thepharmaceutical composition is reconstituted and to the inside surface ofa syringe used to inject the pharmaceutical composition. Adhesion of aprotein active ingredient to surfaces can lead to loss of activeingredient and to denaturation of the remaining retained protein activeingredient, both of which reduce the total activity of the activeingredient present in the pharmaceutical composition, and; (2) reducingdenaturation of the active ingredient which can occur upon preparationof a low dilution solution of the active ingredient.

As well as being able to stabilize a protein active ingredient in apharmaceutical composition, human serum albumin also has the advantageof generally negligible immunogenicity when injected into a humanpatient. A compound with an appreciable immunogenicity can cause theproduction of antibodies against it which can lead to an anaphylacticreaction and/or to the development of drug resistance, with the diseaseor disorder to be treated thereby becoming potentially refractory to thepharmaceutical composition which has an immunogenic component.

Unfortunately, despite its known stabilizing effect, significantdrawbacks exist to the use of human serum albumin in a pharmaceuticalcomposition. For example human serum albumins are expensive andincreasingly difficult to obtain. Furthermore, blood products such asalbumin, when administered to a patient can subject the patient to apotential risk of receiving blood borne pathogens or infectious agents.Thus, it is known that the possibility exists that the presence ofalbumin in a pharmaceutical composition can result in inadvertentincorporation of infectious elements into the pharmaceuticalcomposition. For example, it has been reported that use of human serumalbumin may transmit prions into a pharmaceutical composition. A prionis a proteinaceous infectious particle which is hypothesized to arise asan abnormal conformational isoform from the same nucleic acid sequencewhich makes the normal protein. It has been further hypothesized thatinfectivity resides in a “recruitment reaction” of the normal isoformprotein to the prion protein isoform at a post translational level.Apparently the normal endogenous cellular protein is induced to misfoldinto a pathogenic prion conformation. Significantly, several lots ofhuman serum albumin have been withdrawn from distribution upon adetermination that a blood donor to a pool from which the albumin wasprepared was diagnosed with Creutzfeldt-Jacob disease.

Creutzfeldt-Jacob disease (sometimes characterized as Alzheimer'sdisease on fast forward) is a rare neurodegenerative disorder of humantransmissible spongiform encephalopathy where the transmissible agent isapparently an abnormal isoform of a prion protein. An individual withCreutzfeldt-Jacob disease can deteriorate from apparent perfect healthto akinetic mutism within six months. Possible iatrogenic transmissionof Creutzfeldt-Jacob disease by human serum albumin transfusion has beenreported and it has been speculated that sufficient protection againstCreutzfeldt-Jacob disease transmission is not provided by the usualmethods of human serum albumin preparation which methods includedisposal of blood cellular elements and heating to 60 degrees C. for 10hours. Thus, a potential risk may exist of acquiring a prion mediateddisease, such as Creutzfeldt-Jacob disease, from the administration of apharmaceutical composition which contains human plasma proteinconcentrates, such as serum albumin.

Gelatin has been used in some protein active ingredient pharmaceuticalcompositions as an albumin substitute. Notably, gelatin is a animalderived protein and therefore carries the same risk of potentialinfectivity which may be possessed by human serum albumin. Hence, it isdesirable to find a substitute for human serum albumin which is not ablood fraction, and preferably, the albumin substitute is not gelatinand is not derived from any animal (i.e. mammalian) source.

Botulinum Toxin

The anaerobic, gram positive bacterium Clostridium botulinum produces apotent polypeptide neurotoxin, botulinum toxin, which causes aneuroparalytic illness in humans and animals referred to as botulism.Clostridium botulinum and its spores are commonly found in soil and thebacterium can grow in improperly sterilized and sealed food containersof home based canneries, which are the cause of many of the cases ofbotulism. The effects of botulism typically appear 18 to 36 hours aftereating the foodstuffs infected with a Clostridium botulinum culture orspores. The botulinum toxin can apparently pass unattenuated through thelining of the gut and attack peripheral motor neurons. Symptoms ofbotulinum toxin intoxication can progress from difficulty walking,swallowing, and speaking to paralysis of the respiratory muscles anddeath.

Botulinum toxin type A is the most lethal natural biological agent knownto man. About 50 picograms of botulinum toxin (purified neurotoxincomplex) type A is a LD₅₀ in mice. Interestingly, on a molar basis,botulinum toxin type A is 1.8 billion times more lethal than diphtheria,600 million times more lethal than sodium cyanide, 30 million times morelethal than cobrotoxin and 12 million times more lethal than cholera.Singh, Critical Aspects of Bacterial Protein Toxins, pages 63-84(chapter 4) of Natural Toxins II, edited by B. R. Singh et al., PlenumPress, New York (1976) (where the stated LD₅₀ of botulinum toxin type Aof 0.3 ng equals 1 U is corrected for the fact that about 0.05 ng ofBOTOX® equals 1 unit). One unit (U) of botulinum toxin is defined as theLD₅₀ upon intraperitoneal injection into female Swiss Webster miceweighing 18-20 grams each. In other words, one unit of botulinum toxinis the amount of botulinum toxin that kills 50% of a group of femaleSwiss Webster mice.

Seven generally immunologically distinct botulinum neurotoxins have beencharacterized, these being respectively botulinum neurotoxin serotypesA, B, C₁, D, E, F, and G, each of which is distinguished byneutralization with type-specific antibodies. The different serotypes ofbotulinum toxin vary in the animal species that they affect and in theseverity and duration of the paralysis they evoke. For example, it hasbeen determined that botulinum toxin type A is 500 times more potent, asmeasured by the rate of paralysis produced in the rat, than is botulinumtoxin type B. Additionally, botulinum toxin type B has been determinedto be non-toxic in primates at a dose of 480 U/kg which is about 12times the primate LD₅₀ for botulinum toxin type A. The botulinum toxinsapparently bind with high affinity to cholinergic motor neurons, aretranslocated into the neuron and block the presynaptic release ofacetylcholine.

Botulinum toxins have been used in clinical settings for the treatmentof neuromuscular disorders characterized by hyperactive skeletalmuscles. Botulinum toxin type A was approved by the U.S. Food and DrugAdministration in 1989 for the treatment of essential blepharospasm,strabismus and hemifacial spasm in patients over the age of twelve.Clinical effects of peripheral injection (i.e. intramuscular orsubcutaneous) botulinum toxin type A are usually seen within one week ofinjection, and often within a few hours after injection. The typicalduration of symptomatic relief (i.e. flaccid muscle paralysis) from asingle intramuscular injection of botulinum toxin type A can be aboutthree months to about six months.

Although all the botulinum toxins serotypes apparently inhibit releaseof the neurotransmitter acetylcholine at the neuromuscular junction,they do so by affecting different neurosecretory proteins and/orcleaving these proteins at different sites. Botulinum toxin A is a zincendopeptidase which can specifically hydrolyze a peptide linkage of theintracellular, vesicle associated protein SNAP-25. Botulinum type E alsocleaves the 25 kiloDalton (kD) synaptosomal associated protein(SNAP-25), but targets different amino acid sequences within thisprotein, as compared to botulinum toxin type A. Botulinum toxin types B,D, F and G act on vesicle-associated protein (VAMP, also calledsynaptobrevin), with each serotype cleaving the protein at a differentsite. Finally, botulinum toxin type C₁ has been shown to cleave bothsyntaxin and SNAP-25. These differences in mechanism of action mayaffect the relative potency and/or duration of action of the variousbotulinum toxin serotypes.

Regardless of serotype, the molecular mechanism of toxin intoxicationappears to be similar and to involve at least three steps or stages. Inthe first step of the process, the toxin binds to the presynapticmembrane of the target neuron through a specific interaction between theheavy chain (H chain) and a cell surface receptor; the receptor isthought to be different for each serotype of botulinum toxin and fortetanus toxin. The carboxyl end segment of the H chain, H_(C), appearsto be important for targeting of the toxin to the cell surface.

In the second step, the toxin crosses the plasma membrane of thepoisoned cell. The toxin is first engulfed by the cell throughreceptor-mediated endocytosis, and an endosome containing the toxin isformed. The toxin then escapes the endosome into the cytoplasm of thecell. This last step is thought to be mediated by the amino end segmentof the H chain, H_(N), which triggers a conformational change of thetoxin in response to a pH of about 5.5 or lower. Endosomes are known topossess a proton pump which decreases intra endosomal pH. Theconformational shift exposes hydrophobic residues in the toxin, whichpermits the toxin to embed itself in the endosomal membrane. The toxinthen translocates through the endosomal membrane into the cytosol.

The last step of the mechanism of botulinum toxin activity appears toinvolve reduction of the disulfide bond joining the H and L chain. Theentire toxic activity of botulinum and tetanus toxins is contained inthe L chain of the holotoxin; the L chain is a zinc (Zn++) endopeptidasewhich selectively cleaves proteins essential for recognition and dockingof neurotransmitter-containing vesicles with the cytoplasmic surface ofthe plasma membrane, and fusion of the vesicles with the plasmamembrane. Tetanus neurotoxin, botulinum toxin B, D, F, and G causedegradation of synaptobrevin (also called vesicle-associated membraneprotein (VAMP)), a synaptosomal membrane protein. Most of the VAMPpresent at the cytosolic surface of the synaptic vesicle is removed as aresult of any one of these cleavage events. Each toxin specificallycleaves a different bond.

The molecular weight of the botulinum toxin protein molecule, for allseven of the known botulinum toxin serotypes, is about 150 kD.Interestingly, the botulinum toxins are released by Clostridialbacterium as complexes comprising the 150 kD botulinum toxin proteinmolecule along with associated non-toxin proteins. Thus, the botulinumtoxin type A complex can be produced by Clostridial bacterium as 900 kD,500 kD and 300 kD forms. Botulinum toxin types B and C₁ are apparentlyproduced as only a 500 kD complex. Botulinum toxin type D is produced asboth 300 kD and 500 kD complexes. Finally, botulinum toxin types E and Fare produced as only approximately 300 kD complexes. The complexes (i.e.molecular weight greater than about 150 kD) are believed to contain anon-toxin hemagglutinin protein and a non-toxin and non-toxicnonhemagglutinin protein. These two non-toxin proteins (which along withthe botulinum toxin molecule can comprise the relevant neurotoxincomplex) may act to provide stability against denaturation to thebotulinum toxin molecule and protection against digestive acids whentoxin is ingested. Additionally, it is possible that the larger (greaterthan about 150 kD molecular weight) botulinum toxin complexes may resultin a slower rate of diffusion of the botulinum toxin away from a site ofintramuscular injection of a botulinum toxin complex. The toxincomplexes can be dissociated into toxin protein and hemagglutininproteins by treating the complex with red blood cells at pH 7.3. Thetoxin protein has a marked instability upon removal of the hemagglutininprotein.

All the botulinum toxin serotypes are made by Clostridium botulinumbacteria as inactive single chain proteins which must be cleaved ornicked by proteases to become neuroactive. The bacterial strains thatmake botulinum toxin serotypes A and G possess endogenous proteases andserotypes A and G can therefore be recovered from bacterial cultures inpredominantly their active form. In contrast, botulinum toxin serotypesC₁, D, and E are synthesized by nonproteolytic strains and are thereforetypically unactivated when recovered from culture. Serotypes B and F areproduced by both proteolytic and nonproteolytic strains and thereforecan be recovered in either the active or inactive form. However, eventhe proteolytic strains that produce, for example, the botulinum toxintype B serotype only cleave a portion of the toxin produced. The exactproportion of nicked to unnicked molecules depends on the length ofincubation and the temperature of the culture. Therefore, a certainpercentage of any preparation of, for example, the botulinum toxin typeB toxin is likely to be inactive, possibly accounting for the knownsignificantly lower potency of botulinum toxin type B as compared tobotulinum toxin type A. The presence of inactive botulinum toxinmolecules in a clinical preparation will contribute to the overallprotein load of the preparation, which has been linked to increasedantigenicity, without contributing to its clinical efficacy.Additionally, it is known that botulinum toxin type B has, uponintramuscular injection, a shorter duration of activity and is also lesspotent than botulinum toxin type A at the same dose level.

In vitro studies have indicated that botulinum toxin inhibits potassiumcation induced release of both acetylcholine and norepinephrine fromprimary cell cultures of brainstem tissue. Additionally, it has beenreported that botulinum toxin inhibits the evoked release of bothglycine and glutamate in primary cultures of spinal cord neurons andthat in brain synaptosome preparations botulinum toxin inhibits therelease of each of the neurotransmitters acetylcholine, dopamine,norepinephrine, CGRP and glutamate.

High quality crystalline botulinum toxin type A can be produced from theHall A strain of Clostridium botulinum with characteristics of ≧3×10⁷U/mg, an A₂₆₀/A₂₇₈ of less than 0.60 and a distinct pattern of bandingon gel electrophoresis. The known Schantz process can be used to obtaincrystalline botulinum toxin type A, as set forth in Schantz, E. J., etal, Properties and use of Botulinum toxin and Other MicrobialNeurotoxins in Medicine, Microbiol Rev. 56: 80-99 (1992). Generally, thebotulinum toxin type A complex can be isolated and purified from ananaerobic fermentation by cultivating Clostridium botulinum type A in asuitable medium. Raw toxin can be harvested by precipitation withsulfuric acid and concentrated by ultramicrofiltration. Purification canbe carried out by dissolving the acid precipitate in calcium chloride.The toxin can then be precipitated with cold ethanol. The precipitatecan be dissolved in sodium phosphate buffer and centrifuged. Upon dryingthere can then be obtained approximately 900 kD crystalline botulinumtoxin type A complex with a specific potency of 3×10⁷ LD₅₀ U/mg orgreater. This known process can also be used, upon separation out of thenon-toxin proteins, to obtain pure botulinum toxins, such as forexample: purified botulinum toxin type A with an approximately 150 kDmolecular weight with a specific potency of 1-2×10⁸ LD₅₀ U/mg orgreater; purified botulinum toxin type B with an approximately 156 kDmolecular weight with a specific potency of 1-2×10⁸ LD₅₀ U/mg orgreater, and; purified botulinum toxin type F with an approximately 155kD molecular weight with a specific potency of 1-2×10⁷ LD₅₀ U/mg orgreater.

Already prepared and purified botulinum toxins and toxin complexessuitable for preparing pharmaceutical formulations can be obtained fromList Biological Laboratories, Inc., Campbell, Calif.; the Centre forApplied Microbiology and Research, Porton Down, U.K.; Wako (Osaka,Japan), as well as from Sigma Chemicals of St Louis, Mo.

It has been reported that BoNt/A has been used in clinical settings asfollows:

-   -   (1) about 75-125 units of BOTOX®¹ per intramuscular injection        (multiple muscles) to treat cervical dystonia;        ¹Available from Allergan, Inc., of Irvine, Calif. under the        tradename BOTOX®.    -   (2) 5-10 units of BOTOX® per intramuscular injection to treat        glabellar lines (brow furrows) (5 units injected intramuscularly        into the procerus muscle and 10 units injected intramuscularly        into each corrugator supercilii muscle);    -   (3) about 30-80 units of BOTOX® to treat constipation by        intrasphincter injection of the puborectalis muscle;    -   (4) about 1-5 units per muscle of intramuscularly injected        BOTOX® to treat blepharospasm by injecting the lateral        pre-tarsal orbicularis oculi muscle of the upper lid and the        lateral pre-tarsal orbicularis oculi of the lower lid.    -   (5) to treat strabismus, extraocular muscles have been injected        intramuscularly with between about 1-5 units of BOTOX®, the        amount injected varying based upon both the size of the muscle        to be injected and the extent of muscle paralysis desired (i.e.        amount of diopter correction desired).    -   (6) to treat upper limb spasticity following stroke by        intramuscular injections of BOTOX® into five different upper        limb flexor muscles, as follows:    -   (a) flexor digitorum profundus: 7.5 U to 30 U    -   (b) flexor digitorum sublimus: 7.5 U to 30 U    -   (c) flexor carpi ulnaris: 10 U to 40 U    -   (d) flexor carpi radialis: 15 U to 60 U    -   (e) biceps brachii: 50 U to 200 U. Each of the five indicated        muscles has been injected at the same treatment session, so that        the patient receives from 90 U to 360 U of upper limb flexor        muscle BOTOX® by intramuscular injection at each treatment        session.    -   (7) to treat migraine, pericranial injected (injected        symmetrically into glabellar, frontalis and temporalis muscles)        injection of 25 U of BOTOX® has showed significant benefit as a        prophylactic treatment of migraine compared to vehicle as        measured by decreased measures of migraine frequency, maximal        severity, associated vomiting and acute medication use over the        three month period following the 25 U injection.

Additionally, intramuscular botulinum toxin has been used in thetreatment of tremor in patients with Parkinson's disease, although ithas been reported that results have not been impressive. Marjama-Lyons,J., et al., Tremor-Predominant Parkinson's Disease, Drugs & Aging16(4);273-278:2000.

It is known that botulinum toxin type A can have an efficacy for up to12 months (European J. Neurology 6 (Supp 4): S111′-S1150:1999), and insome circumstances for as long as 27 months. The Laryngoscope109:1344-1346:1999. However, the usual duration of an intramuscularinjection of Botox® is typically about 3 to 4 months.

The success of botulinum toxin type A to treat a variety of clinicalconditions has led to interest in other botulinum toxin serotypes.Additionally, pure botulinum toxin has been used in humans. see e.g.Kohl A., et al., Comparison of the effect of botulinum toxin A (Botox(R)) with the highly-purified neurotoxin (NT201) in the extensordigitorum brevis muscle test, Mov Disord 2000;15(Suppl 3):165 Hence, apharmaceutical composition can be prepared using a pure botulinum toxin.The botulinum toxin molecule (about 150 kDa), as well as the botulinumtoxin complexes (about 300-900 kDa), such as the toxin type A complexare also extremely susceptible to denaturation due to surfacedenaturation, heat, and alkaline conditions. Inactivated toxin formstoxoid proteins which may be immunogenic. The resulting antibodies canrender a patient refractory to toxin injection.

As with enzymes generally, the biological activities of the botulinumtoxins (which are intracellular peptidases) are dependant, at least inpart, upon their three dimensional conformation. Thus, botulinum toxintype A is detoxified by heat, various chemicals surface stretching andsurface drying. Additionally, it is known that dilution of the toxincomplex obtained by the known culturing, fermentation and purificationto the much, much lower toxin concentrations used for pharmaceuticalcomposition formulation results in rapid detoxification of the toxinunless a suitable stabilizing agent is present. Dilution of the toxinfrom milligram quantities to a solution containing nanograms permilliliter presents significant difficulties because of the rapid lossof specific toxicity upon such great dilution. Since the toxin may beused months or years after the toxin containing pharmaceuticalcomposition is formulated, the toxin must be stabilized with astabilizing agent. To date, the only successful stabilizing agent forthis purpose has been the animal derived proteins human serum albuminand gelatin. And as indicated, the presence of animal derived proteinsin the final formulation presents potential problems in that certainstable viruses, prions, or other infectious or pathogenic compoundscarried through from donors can contaminate the toxin.

Furthermore, any one of the harsh pH, temperature and concentrationrange conditions required to lyophilize (freeze-dry) or vacuum dry abotulinum toxin containing pharmaceutical composition into a toxinshipping and storage format (ready for use or reconstitution by aphysician) can detoxify the toxin. Thus, animal derived or donor poolproteins such as gelatin and serum albumin have been used with somesuccess to stabilize botulinum toxin.

A commercially available botulinum toxin containing pharmaceuticalcomposition is sold under the trademark BOTOX® (available from Allergan,Inc., of Irvine, Calif.). BOTOX® consists of a purified botulinum toxintype A complex, human serum albumin, and sodium chloride packaged insterile, vacuum-dried form.

The botulinum toxin type A is made from a culture of the Hall strain ofClostridium botulinum grown in a medium containing N-Z amine and yeastextract. The botulinum toxin type A complex is purified from the culturesolution by a series of acid precipitations to a crystalline complexconsisting of the active high molecular weight toxin protein and anassociated hemagglutinin protein. The crystalline complex isre-dissolved in a solution containing saline and albumin and sterilefiltered (0.2 microns) prior to vacuum-drying. BOTOX® can bereconstituted with sterile, non-preserved saline prior to intramuscularinjection. Each vial of BOTOX® contains about 100 units (U) ofClostridium botulinum toxin type A complex, 0.5 milligrams of humanserum albumin and 0.9 milligrams of sodium chloride in a sterile,vacuum-dried form without a preservative.

To reconstitute vacuum-dried BOTOX® sterile normal saline without apreservative (0.9% Sodium Chloride injection) is used by drawing up theproper amount of diluent in the appropriate size syringe. Since BOTOX®is denatured by bubbling or similar violent agitation, the diluent isgently injected into the vial. For sterility reasons, BOTOX® should beadministered within four hours after reconstitution. During this timeperiod, reconstituted BOTOX® is stored in a refrigerator (2° to 8° C.).Reconstituted BOTOX® is clear, colorless and free of particulate matter.The vacuum-dried product is stored in a freezer at or below −5° C.

Other commercially available botulinum toxin containing pharmaceuticalcompositions include Dysport® (Clostridium botulinum type A toxinhemagglutinin complex with human serum albumin and lactose in theformulation, available from Ipsen Limited, Berkshire, U.K. as a powderto be reconstituted with 0.9% sodium chloride before use), and MyoBloc™(an injectable solution comprising botulinum toxin type B, human serumalbumin, sodium succinate, and sodium chloride at about pH 5.6,available from Elan Corporation, Dublin, Ireland).

It has been reported that a suitable alternative to human serum albuminas a botulinum toxin stabilizer may be another protein or alternativelya low molecular weight (non-protein) compound. Carpender et al.,Interactions of Stabilizing Additives with Proteins DuringFreeze-Thawing and Freeze-Drying, International Symposium on BiologicalProduct Freeze-Drying and Formulation, 24-26 Oct. 1990; Karger (1992),225-239.

Many substances commonly used as carriers and bulking agents inpharmaceutical compositions have proven to be unsuitable as albuminreplacements in a Clostridial toxin containing pharmaceuticalcomposition. For example, the disaccharide cellobiose has been found tobe unsuitable as a botulinum toxin stabilizer. Thus, it is known thatthe use of cellobiose as an excipient in conjunction with albumin andsodium chloride results in a much lower level of toxicity (10% recovery)after lyophilization of crystalline botulinum toxin type A with theseexcipients, as compared to the toxicity after lyophilization with onlyhuman serum albumin (>75% to >90% recovery). Goodnough et al.,Stabilization of Botulinum Toxin Type A During Lyophilization, App &Envir. Micro. 58 (10) 3426-3428 (1992).

Furthermore, saccharides, including polysaccharides, are in general poorcandidates to serve as protein stabilizers. Thus, it is known that apharmaceutical composition containing a protein active ingredient isinherently unstable if the protein formulation comprises a saccharide(such as glucose or a polymer of glucose) or carbohydrates becauseproteins and glucose are known to interact together and to undergo thewell-described Maillard reaction, due to the reducing nature of glucoseand glucose polymers. Much work has been dedicated to mostlyunsuccessful attempts at preventing this protein-saccharide reaction by,for example, reduction of moisture or use of non-reducing sugars.Significantly, the degradative pathway of the Maillard reaction canresult in a therapeutic insufficiency of the protein active ingredient.A pharmaceutical formulation comprising protein and a reducingsaccharide, carbohydrate or sugar, such as a glucose polymer, istherefore inherently unstable and cannot be stored for a long period oftime without significant loss of the active ingredient protein's desiredbiological activity.

Notably, one of the reasons human serum albumin can function effectivelyas a stabilizer of a protein active ingredient in a pharmaceuticalcomposition is because, albumin, being a protein, does not undergo theMaillard reaction with the protein active ingredient in a pharmaceuticalcomposition. Hence, one would expect to find and to look for asubstitute for human serum albumin amongst other proteins.

Finding an appropriate substitute for human serum albumin as astabilizer of the botulinum toxin present in a pharmaceuticalcomposition is difficult and problematic because human serum albumin isbelieved to function in a pharmaceutical composition as more than a merebulking agent. Thus, albumin apparently can interact with botulinumtoxin so as to increase the potency of the neurotoxin. For example, itis known that bovine serum albumin can act as more than a merestabilizing excipient for botulinum toxin type A, since bovine serumalbumin apparently also accelerates the rate of catalysis of syntheticpeptide substrates, which substrates resemble the SNAP-25 intraneuronalsubstrate for botulinum toxin type A Schmidt, et al., EndoproteinaseActivity of Type A Botulinum Neurotoxin Substrate Requirements andActivation by Serum Albumin, J. of Protein Chemistry, 16 (1), 19-26(1997). Thus, albumin may have a potentiating effect, apparently byaffecting rate kinetics, upon the intracellular proteolytic action of abotulinum toxin upon the toxin's substrate. This potentiating effect maybe due to albumin which has accompanied the botulinum toxin uponendocytosis of the toxin into a target neuron or the potentiating effectmay be due to the pre-existing presence cytoplasmic albumin within theneuron protein prior to endocytosis of the botulinum toxin.

The discovery of the presence of a kinetic rate stimulatory effect bybovine serum albumin upon the proteolytic activity of botulinum toxintype A renders the search for a suitable substitute for albumin in abotulinum toxin containing pharmaceutical formulation especiallyproblematic. Thus, an albumin substitute with desirable toxinstabilization characteristics may have an unknown and possiblydeleterious effect upon the rate of substrate catalysis by the toxin,since at least with regard to bovine serum albumin the twocharacteristics (toxin stabilization and toxin substrate catalysispotentiation) are apparently inherent to the same albumin excipient.This potentiating effect of albumin shows that albumin does not act as amere excipient in the formulation and therefore renders the search for asuitable substitute for albumin more difficult.

Additionally there are many unique characteristics of botulinum toxinand its formulation into a suitable pharmaceutical composition whichconstrain and hinder and render the search for a replacement for thealbumin used in current botulinum toxin containing pharmaceuticalformulations very problematic. Examples of four of these uniquecharacteristics follow.

First, botulinum toxin is a relatively large protein for incorporationinto a pharmaceutical formulation (the molecular weight of the botulinumtoxin type A complex is 900 kD) and is therefore is inherently fragileand labile. The size of the toxin complex makes it much more friable andlabile than smaller, less complex proteins, thereby compounding theformulation and handling difficulties if toxin stability is to bemaintained. Hence, an albumin replacement must be able to interact withthe toxin in a manner which does not denature, fragment or otherwisedetoxify the toxin molecule or cause disassociation of the non-toxinproteins present in the toxin complex.

Second, as the most lethal known biological product, exceptional safety,precision, and accuracy is called for at all steps of the formulation ofa botulinum toxin containing pharmaceutical composition. Thus, apreferred potential albumin replacer should not itself be toxic ordifficult to handle so as to not exacerbate the already extremelystringent botulinum toxin containing pharmaceutical compositionformulation requirements.

Third, since botulinum toxin was the first microbial toxin to beapproved (by the FDA in 1989) for injection for the treatment of humandisease, specific protocols had to be developed and approved for theculturing, bulk production, formulation into a pharmaceutical and use ofbotulinum toxin. Important considerations are toxin purity and dose forinjection. The production by culturing and the purification must becarried out so that the toxin is not exposed to any substance that mightcontaminate the final product in even trace amounts and cause unduereactions in the patient. These restrictions require culturing insimplified medium without the use of animal meat products andpurification by procedures not involving synthetic solvents or resins.Preparation of toxin using enzymes, various exchangers, such as thosepresent in chromatography columns and synthetic solvents can introducecontaminants and are therefore excluded from preferred formulationsteps. Furthermore, botulinum toxin type A is readily denatured attemperatures above 40 degrees C., loses toxicity when bubbles form atthe air/liquid interface, and denatures in the presence of nitrogen orcarbon dioxide.

Fourth, particular difficulties exist to stabilize botulinum toxin typeA, because type A consists of a toxin molecule of about 150 kD innoncovalent association with nontoxin proteins weighing about 750 kD.The nontoxin proteins are believed to preserve or help stabilize thesecondary and tertiary structures upon which toxicity is dependant.Procedures or protocols applicable to the stabilization of nonproteinsor to relatively smaller proteins are not applicable to the problemsinherent with stabilization of the botulinum toxin complexes, such asthe 900 kD botulinum toxin type A complex. Thus while from pH 3.5 to 6.8the type A toxin and non toxin proteins are bound togethernoncovalently, under slightly alkaline conditions (pH >7.1) the verylabile toxin is released from the toxin complex. As set forthpreviously, pure botulinum toxin (i.e the 150 kD molecule) has beenproposed as the active ingredient in a pharmaceutical composition.

In light of the unique nature of botulinum toxin and the requirementsset forth above, the probability of finding a suitable albuminreplacement for the human serum albumin used in current botulinum toxincontaining pharmaceutical compositions must realistically be seen toapproach zero. Prior to the present invention, only the animal derivedproteins, human serum albumin and gelatin, had been known to haveutility as suitable stabilizers of the botulinum toxin present in apharmaceutical formulation. Thus, albumin, by itself or with one or moreadditional substances such as sodium phosphate or sodium citrate, isknown to permit high recovery of toxicity of botulinum toxin type Aafter lyophilization. Unfortunately, as already set forth, human serumalbumin, as a pooled blood product, can, at least potentially, carryinfectious or disease causing elements when present in a pharmaceuticalcomposition. Indeed, any animal product or protein such as human serumalbumin or gelatin can also potentially contain pyrogens or othersubstances that can cause adverse reactions upon injection into apatient.

Chinese patent application CN 1215084A discusses an albumin freebotulinum toxin type A formulated with gelatin, an animal derivedprotein. U.S. Pat. No. 6,087,327 also discloses a composition ofbotulinum toxin types A and B formulated with gelatin. Theseformulations therefore do not eliminate the risk of transmitting ananimal protein derived or accompanying infectious element.

Acetylcholine

Typically only a single type of small molecule neurotransmitter isreleased by each type of neuron in the mammalian nervous system. Theneurotransmitter acetylcholine is secreted by neurons in many areas ofthe brain, but specifically by the large pyramidal cells of the motorcortex, by several different neurons in the basal ganglia, by the motorneurons that innervate the skeletal muscles, by the preganglionicneurons of the autonomic nervous system (both sympathetic andparasympathetic), by the postganglionic neurons of the parasympatheticnervous system, and by some of the postganglionic neurons of thesympathetic nervous system. Essentially, only the postganglionicsympathetic nerve fibers to the sweat glands, the piloerector musclesand a few blood vessels are cholinergic as most of the postganglionicneurons of the sympathetic nervous system secret the neurotransmitternorepinephrine. In most instances acetylcholine has an excitatoryeffect. However, acetylcholine is known to have inhibitory effects atsome of the peripheral parasympathetic nerve endings, such as inhibitionof heart rate by the vagal nerve.

The efferent signals of the autonomic nervous system are transmitted tothe body through either the sympathetic nervous system or theparasympathetic nervous system. The preganglionic neurons of thesympathetic nervous system extend from preganglionic sympathetic neuroncell bodies located in the intermediolateral horn of the spinal cord.The preganglionic sympathetic nerve fibers, extending from the cellbody, synapse with postganglionic neurons located in either aparavertebral sympathetic ganglion or in a prevertebral ganglion. Since,the preganglionic neurons of both the sympathetic and parasympatheticnervous system are cholinergic, application of acetylcholine to theganglia will excite both sympathetic and parasympathetic postganglionicneurons.

Acetylcholine activates two types of receptors, muscarinic and nicotinicreceptors. The muscarinic receptors are found in all effector cellsstimulated by the postganglionic, neurons of the parasympathetic nervoussystem as well as in those stimulated by the postganglionic cholinergicneurons of the sympathetic nervous system. The nicotinic receptors arefound in the adrenal medulla, as well as within the autonomic ganglia,that is on the cell surface of the postganglionic neuron at the synapsebetween the preganglionic and postganglionic neurons of both thesympathetic and parasympathetic systems. Nicotinic receptors are alsofound in many nonautonomic nerve endings, for example in the membranesof skeletal muscle fibers at the neuromuscular junction.

Acetylcholine is released from cholinergic neurons when small, clear,intracellular vesicles fuse with the presynaptic neuronal cell membrane.A wide variety of non-neuronal secretory cells, such as, adrenal medulla(as well as the PC12 cell line) and pancreatic islet cells releasecatecholamines and parathyroid hormone, respectively, from largedense-core vesicles. The PC12 cell line is a clone of ratpheochromocytoma cells extensively used as a tissue culture model forstudies of sympathoadrenal development. Botulinum toxin inhibits therelease of both types of compounds from both types of cells in vitro,permeabilized (as by electroporation) or by direct injection of thetoxin into the denervated cell. Botulinum toxin is also known to blockrelease of the neurotransmitter glutamate from cortical synaptosomescell cultures.

A neuromuscular junction is formed in skeletal muscle by the proximityof axons to muscle cells. A signal transmitted through the nervoussystem results in an action potential at the terminal axon, withactivation of ion channels and resulting release of the neurotransmitteracetylcholine from intraneuronal synaptic vesicles, for example at themotor endplate of the neuromuscular junction. The acetylcholine crossesthe extracellular space to bind with acetylcholine receptor proteins onthe surface of the muscle end plate. Once sufficient binding hasoccurred, an action potential of the muscle cell causes specificmembrane ion channel changes, resulting in muscle cell contraction. Theacetylcholine is then released from the muscle cells and metabolized bycholinesterases in the extracellular space. The metabolites are recycledback into the terminal axon for reprocessing into further acetylcholine.

Hydroxyethyl Starch

A polysaccharide can be made up of hundreds or even thousands ofmonosaccharide units held together by glycoside (ether) linkages. Twoimportant polysaccharides are cellulose and starch. Cellulose is thechief structural material in plants, giving plants their rigidity andform. Starch makes up the reserve food supply of plants and is foundmainly in various seeds and tubers.

Starch occurs as granules whose size and shape are characteristic of theplant from which the starch is obtained. In general about 80% of starchis a water insoluble fraction called amylopectin. Amylopectin is made upof chains of D-glucose (as glucopyranose) units, each unit being joinedby an alpha glycoside linkage to C-4 of the next glucose unit. Likestarch, cellulose is also made up of chains of D-glucose units, whereeach unit is joined by a glucoside linkage to the C-4 of the next unit.Unlike starch though, the glycoside linkages in cellulose are betalinkages. Treatment of cellulose with sulfuric acid and acetic anhydrideyields the disaccharide cellobiose. As previously set forth, attempts tostabilize botulinum toxin using cellobiose have been unsuccessful.

A particular starch derivative which can be obtained by treating starchwith pyridine and ethylene chlorohydrin, is 2-hydroxyethyl starch, alsocalled hetastarch. U.S. Pat. No. 4,457,916 discloses a combination of anonionic surfactant and hydroxyethyl starch to stabilize aqueoussolutions of tumor necrosis factor (TNF).

Additionally, a 6% aqueous solution of 2-hydroxyethyl starch(hetastarch) (available from Du Pont Pharma, Wilmington, Del. under thetrade name HESPAN®, 6% hetastarch in 0.9% sodium chloride injection) isknown. Albumin is known to act as a plasma volume expander uponintravenous administration to a patient. HESPAN® has also beenadministrated to patients to achieve a plasma volume expansion effectand in that sense intravenous HESPAN® can be considered a replacementfor intravenous albumin.

Hetastarch is an artificial colloid derived from a waxy starch composedalmost entirely of amylopectin. Hetastarch can be obtained byintroducing hydroxyethyl ether groups onto glucose units of the starch,and the resultant material can then be hydrolyzed to yield a productwith a molecular weight suitable for use as a plasma volume expander.Hetastarch is characterized by its molar substitution and also by itsmolecular weight. The molar substitution can be approximately 0.75,meaning that hetastarch is etherified to the extent that for every 100glucose units of hetastarch there are, on average, approximately 75hydroxyethyl substituent groups. The average molecular weight ofhetastarch is approximately 670 kD with a range of 450 kD to 800 kD andwith at least 80% of the polymer units falling within the range of 20 kDto 2,500 kD. Hydroxyethyl groups are attached by ether linkagesprimarily at C-2 of the glucose unit and to a lesser extent at C-3 andC-6. The polymer resembles glycogen, and the polymerized D-glucose unitsare joined primarily by α-1,4 linkages with occasional α-1,6 branchinglinkages. The degree of branching is approximately 1:20, meaning thatthere is an average of approximately one α-1,6 branch for every 20glucose monomer units. Hetastarch is comprised of more than 90%amylopectin.

The plasma volume expansion produced by HESPAN® can approximate thatobtained with albumin. Hetastarch molecules below 50 kD molecular weightare rapidly eliminated by renal excretion and a single dose ofapproximately 500 mL of HESPAN® (approximately 30 g) results inelimination in the urine of approximately 33% of the administeredHESPAN® within about 24 hours. The hydroxyethyl group of hydroxyethylstarch is not cleaved in vivo, but remains intact and attached toglucose units when excreted. Significant quantities of glucose are notproduced as hydroxyethylation prevents complete metabolism of thesmaller hydroxyethyl starch polymers

Cellulose can likewise be converted to a hydroxyethyl cellulose. Theaverage molecular weight of 2-hydroxyethyl cellulose (a 2-hydroxyethylether of cellulose) is about 90 kD. Unfortunately, hydroxyethylcellulose, unlike hydroxyethyl starch, is highly reactive and thereforeunsuited for use as a stabilizer of a protein active ingredient in apharmaceutical formulation.

Pharmaceutical Compositions for Veterinary Use

Non human animals (or “animals” in this section) can suffer frommaladies and injuries that are painful and difficult to treat. Forexample, some canine breeds, such as German Shepherds, commonly sufferfrom hip dysplasia, and may require corrective surgery, such as hipreplacement. Horses may suffer from gastrointestinal disorders, such ascolic, that may result in significant pain. Similarly, race horsesfrequently suffer from fractured or broken bones. Horses may also sufferflexor tendon and suspensory ligament injury. Ponies are particularlysusceptible to founder, a painful crippling disorder specific to horses.Additionally, juvenile birds, such as parrots can be afflicted withscoliosis

Additionally, non human animals may be subjected to painful andirreversible procedures, such as denervation, to modify involuntarynatural behaviors, for example ear and tail twitching, in show horsesfor example. Such drastic procedures are performed for cosmetic reasons.No other humane remedy currently exists to correct such undesirabletraits. These procedures permanently damage the animals.

Animals may also cause severe injury to themselves due to what would bea mild condition in humans. Wounds are often exacerbated by stallrubbing in horses resulting in insufficient healing and chronic sores.Sores and skin irritation can result in serious infection in thismanner. Other maladies not seen in human patients exist in animals. Forexample, flies and parasites cause discomfort and act as vectors fordisease. Dogs often require hospitalization and or restraint due tobiting and scratching related to fleas and mange. Collars are oftenplaced around the animal's neck to prevent the animal from scratchingears affected by mites or surgical procedures. These maladies, ifmediated for a time sufficient for the affected area to heal or theparasite to be removed, can be avoided, relieving the animal ofsuffering and symptoms.

A significant barrier in treating animals and promoting their recoveryfrom injury or surgery is due to an inability to instruct the animalabout proper rest and rehabilitation procedures. The difficulty ofimmobilizing an animal may result in re-injury, self-injury, and/orimproper healing. Minor injuries often become catastrophic due to thedifficulty of immobilizing animals during and after treatment. Manytimes the animal must be destroyed. In addition, wild animals (e.g.,non-domestic animals) that pose a danger to others or themselves mayneed to be immobilized to safely return the animal to its nativeenvironment. Typically, these animals are tranquilized and moved, or arekilled.

Another problem when treating animals arises from the difficulty inadministering proper dosages. Animals do not readily swallow oral dosageforms of medicine and often offer violent resistance to injections.Frequent application of short-acting drugs may therefore not bepossible. Accordingly, as opposed to humans, animals may requirelong-acting, single injection pharmaceuticals to receive adequatebenefit from the drug.

While pharmaceutical compositions containing human protein may notpresent problems from a single administration, except in certainindividuals or species, repeated dosing may initiate immune responses inanimals, including anaphylactic shock. As discussed above, currentformulations of botulinum toxin include human serum albumin (HSA) as astabilizing excipient. These formulations may present serious problemsfor veterinary use because the presence of a human protein may induceimmunogenic responses in other animal species, limiting the efficacy,utility, and safety of the drug. Formulations which do not contain HSAas an excipient, however, should not produce these antibodies. The lackof suitable formulations of botulinum toxin for use in treatingnon-human animals has impeded the development of methods of usingbotulinum toxin in veterinary medicine.

Indeed, the majority, if not all, of research regarding the therapeuticaspects of botulinum toxin has focused on the use of botulinum toxin fortreating human diseases or ailments. As a necessary precursor, botulinumtoxin has experimentally been administered to animals to examine itssafety and efficacy in animal models of human diseases. For example,botulinum toxin type B has been administered to mice to treat thermalhyperalgesia (Tsuda et al., (1999) “In vivo pathway of thermalhyperalgesia by intrathecal administration of β-methylene ATP in mousespinal cord: Involvement of the glutamate-NMDA receptor system”, Br. J.Pharmacol., 127(2):449-456). In addition, botulinum toxin type A hasbeen:

-   -   administered to piglets to relieve lower esophageal sphincter        (LES) pressure (U.S. Pat. No. 5,437,291, entitled “Method for        treating gastrointestinal muscle disorders and other smooth        muscle dysfunction”);    -   injected into gastric wall of rats to treat obesity (Gui et        al., (2000) “Botulinum toxin injected in the gastric wall        reduces body weight and food intake in rats”, Aliment Pharmacol        Ther., 14(6):829-834);    -   used to assess the efficacy of the neurotoxin to produce better        scar formation from facial cosmetic surgery in non-human        primates (Gassner et al., (2000) Plast. Reconst. Surg.,        105(6):1948-1953);    -   administered to rats to examine its ability to reduce pain (Aoki        et al., (2000) “Methods for treating pain”, U.S. Pat. No.        6,113,915;    -   administered to rats and dogs to alter vocal cord dynamics for        treating spasmodic dysphonia and vocal cord paralysis in humans        (Inagi et al., (1998) “Physiologic assessment of botulinum toxin        effects in the rat larynx”, Laryngoscope, 108(7):1048-1054; and        Cohen and Thompson (1987) “Use of botulinum toxin to lateralize        true vocal cords: a biochemical method to relieve bilateral        abductor vocal cord paralysis”, Ann. Otol. Rhinol. Laryngol.,        96(5):534-41); and    -   administered to the obicularis ocuji muscle of the guinea pig to        examine the efficacy of the toxin to treat eye lid spasms (Horn        et al., (1993) “Botulinum toxin paralysis of the orbicularis        oculi muscle. Types and time course of alterations in muscle        structure, physiology and lid kinematics”, Exp. Brain Res.,        96(1):39-53).

In addition, a botulinum toxin has been administered to rabbits toassess the immunogenicity of the toxin when conjugated with human serumalbumin (HSA).

Because the administration of botulinum toxin to animals has only beenexamined experimentally as a model for treating humans with botulinumtoxin, researchers have not been concerned with long-term effects of theneurotoxin on animals. In particular, the art has not addressed theimmunogenicity of the botulinum toxin compositions in the non-humananimals receiving the neurotoxin. Thus, it would be beneficial to have aneurotoxin composition with reduced immunogenicity for use in veterinarycare, and convenient and effective methods for immobilizing or treatingnon-human animals.

What is needed therefore is a botulinum toxin containing pharmaceuticalcomposition which is free of animal derived proteins such as a bloodpooled or blood fraction derived serum albumin or gelatin.

DRAWINGS

FIG. 1 is a graph (a chromatogram) which shows the molecular weightdistribution (higher molecular weight moieties are to the left) of acommercially available human serum albumin (top graph A) and of acommercially available recombinant albumin (bottom graph B). The x axisrepresents elution time in minutes using size exclusion HPLC (highperformance liquid chromatography) in TSK-3000 buffer. The y axisrepresents the UV response at the detection wavelength of 280 nm.

FIG. 2 is a graph (a chromatogram) which shows the molecular weightdistribution (higher molecular weight moieties are to the left) ofFormulation A (an HSA botulinum toxin formulation, see Table 1) (topgraph C) and of Formulation B (a rHSA botulinum toxin formulation, seeTable 1) (bottom graph D). The x and y axes are as in FIG. 1.

FIG. 3 is a bar graph which shows the potency in mouse LD₅₀ units (the yaxis) of six different botulinum toxin formulations (A-F) (along the xaxis) upon the making of the formulations (i.e. at T₀) and after sixmonths storage at −5 degrees C. (i.e. at T₆).

SUMMARY

The present invention meets this need and provides a botulinum toxinpharmaceutical composition which is free of animal derived proteins suchas a blood pooled or blood fraction derived human serum albumin orgelatin. One embodiment of the present invention is a botulinum toxinpharmaceutical composition wherein the primary stabilizer present in theformulation is a recombinantly made albumin.

The present invention encompasses new pharmaceutical compositions,embodiments of which can provide a superior replacement (i.e. by use ofa recombinant albumin, with or without additional stabilizers) for theserum or native albumin present as a primary stabilizer in apharmaceutical composition. Thus, my invention encompasses new,stabilized botulinum toxin pharmaceutical compositions, which can havethe additional and desirable characteristics of enhanced potency and/oran enhanced antimicrobial activity. The serum or native albuminreplacement compound used has the characteristic of low, and preferablynegligible, immunogenicity when injected into a patient. Additionally,the preferred human serum albumin replacer has a rapid rate of clearancefrom the body after injection of the pharmaceutical composition.

The present invention also provides a pharmaceutical composition whichis specific to non human animals.

Definitions

As used herein, the words or terms set forth below have the followingdefinitions.

“About” means that the item, parameter or term so qualified encompassesa range of plus or minus ten percent above and below the value of thestated item, parameter or term.

“Administration”, or “to administer” means the step of giving (i.e.administering) a pharmaceutical composition to a subject. Thepharmaceutical compositions disclosed herein are “locally administered”.Systemic (i.e. intravenous or oral) routes of administration areexcluded from the scope of the present invention, to the extent that asystemic administration would result in systemic effects of asystemically administered active ingredient. Systemic administration ofa targeted active ingredient which does not result in systemic effectsis not excluded from the scope of the present invention. Localadministration includes, but is not limited to, intramuscular (i.m.)administration, intradermal administration, subcutaneous administration,intrathecal administration, intraperitoneal (i.p.) administration,topical contact, and implantation of a slow-release device such aspolymeric implant or miniosmotic pump.

“Amino acid” Includes Polyamino Acids.

“Animal protein free” means the absence of blood derived, blood pooledand other animal derived products or compounds. “Animal” means a mammal(such as a human), bird, reptile, fish, insect, spider or other animalspecies. “Animal” excludes microorganisms, such as bacteria. Thus, ananimal protein free pharmaceutical composition can include a Clostridialneurotoxin. For example, an animal protein free pharmaceuticalcomposition means a pharmaceutical composition which is eithersubstantially free or essentially free or entirely free of a serumderived albumin, gelatin and other animal derived proteins, such asimmunoglobulins. An example of an animal protein free pharmaceuticalcomposition is a pharmaceutical composition which comprises or whichconsists of a botulinum toxin (as the active ingredient) and arecombinantly made albumin or other recombinantly made stabilizer orexcipient.

“Botulinum toxin” means a neurotoxin produced by Clostridium botulinum,as well as a botulinum toxin (or the light chain or the heavy chainthereof) made recombinantly by a non-Clostridial species. The phrase“botulinum toxin”, as used herein, encompasses the botulinum toxinserotypes A, B, C, D, E, F and G. Botulinum toxin, as used herein, alsoencompasses both a botulinum toxin complex (i.e. the 300, 600 and 900kDa complexes) as well as the purified botulinum toxin (i.e. about 150kDa). “Purified botulinum toxin” is defined as a botulinum toxin that isisolated, or substantially isolated, from other proteins, includingproteins that form a botulinum toxin complex. A purified botulinum toxinmay be greater than 95% pure, and preferably is greater than 99% pure.

“Clostridial neurotoxin” means a neurotoxin produced from, or native to,a Clostridial bacterium, such as Clostridium botulinum, Clostridiumbutyricum or Clostridium beratti, as well as a Clostridial neurotoxinmade recombinantly by a non-Clostridial species.

“Domesticated animal” means an animal that has adapted to humanhabitats. Domesticated animals, as defined herein, are tame animals.Accordingly, animals that live with humans, such as pets, aredomesticated animals. Farm animals are also domesticated animals asdisclosed herein. Laboratory animals are not domesticated animals inreference to the disclosure herein. Humans are not domesticated animals.

“Enhanced antimicrobial activity” with regard to a botulinum toxincontaining pharmaceutical composition means that the composition (i.e. azinc containing botulinum toxin pharmaceutical composition with eitherHSA or rHSA as the primary stabilizer) does not support or supports to alesser extent the growth of a particular microorganism, as compared to areference (i.e. lacking zinc) botulinum toxin pharmaceuticalcomposition.

“Enhanced potency” with regard to a botulinum toxin containingpharmaceutical composition means that the composition has a potency (asdetermined, for example, by the mouse LD₅₀ assay) which is from at least5% and up to 40%, or more, greater than the potency of a referencebotulinum toxin pharmaceutical composition. A reference botulinum toxinpharmaceutical composition can contain a botulinum toxin, sodiumchloride, HSA and no zinc.

“Entirely free (i.e. “consisting of” terminology) means that within thedetection range of the instrument or process being used, the substancecannot be detected or its presence cannot be confirmed.

“Essentially free” (or “consisting essentially of”) means that onlytrace amounts of the substance can be detected.

“Immobilizing” means a step that prevents a subject from moving one ormore body parts. If a sufficient number of body parts are immobilized,the subject will accordingly be immobilized. Thus, “immobilizing”encompasses the immobilization of a body part, such as a limb, and/orthe complete immobilization of a subject.

“Modified botulinum toxin” means a botulinum toxin that has had at leastone of its amino acids deleted, modified, or replaced, as compared to anative botulinum toxin. Additionally, the modified botulinum toxin canbe a recombinantly produced neurotoxin, or a derivative or fragment of arecombinantly made neurotoxin. A modified botulinum toxin retains atleast one biological activity of the native botulinum toxin, such as,the ability to bind to a botulinum toxin receptor, or the ability toinhibit neurotransmitter release from a neuron. One example of amodified botulinum toxin is a botulinum toxin that has a light chainfrom one botulinum toxin serotype (such as serotype A), and a heavychain from a different botulinum toxin serotype (such as serotype B).Another example of a modified botulinum toxin is a botulinum toxincoupled to a neurotransmitter, such as substance P.

“Patient” means a human or non-human subject receiving medical orveterinary care. Accordingly, as disclosed herein, the compositions maybe used in treating any animal, such as mammals.

“Pharmaceutical composition” means a formulation in which an activeingredient can be a neurotoxin, such as a Clostridial neurotoxin. Theword “formulation” means that there is at least one additionalingredient in the pharmaceutical composition besides a neurotoxin activeingredient. A pharmaceutical composition is therefore a formulationwhich is suitable for diagnostic or therapeutic administration (i.e. byintramuscular or subcutaneous injection or by insertion of a depot orimplant) to a subject, such as a human patient. The pharmaceuticalcomposition can be: in a lyophilized or vacuum dried condition; asolution formed after reconstitution of the lyophilized or vacuum driedpharmaceutical composition with saline or water, or; as a solution whichdoes not require reconstitution. The neurotoxin active ingredient can beone of the botulinum toxin serotypes A, B, C₁, D, E, F or G or a tetanustoxin, all of which can be made natively by Clostridial bacteria. Asstated, a pharmaceutical composition can be liquid or solid, for examplevacuum-dried. The constituent ingredients of a pharmaceuticalcomposition can be included in a single composition (that is all theconstituent ingredients, except for any required reconstitution fluid,are present at the time of initial compounding of the pharmaceuticalcomposition) or as a two-component system, for example a vacuum-driedcomposition reconstituted with a diluent such as saline which diluentcontains an ingredient not present in the initial compounding of thepharmaceutical composition. A two-component system provides the benefitof allowing incorporation of ingredients which are not sufficientlycompatible for long-term shelf storage with the first component of thetwo component system. For example, the reconstitution vehicle or diluentmay include a preservative which provides sufficient protection againstmicrobial growth for the use period, for example one-week ofrefrigerated storage, but is not present during the two-year freezerstorage period during which time it might degrade the toxin. Otheringredients, which may not be compatible with a Clostridial toxin orother ingredients for long periods of time, may be incorporated in thismanner; that is, added in a second vehicle (i.e. in the reconstitutionfluid) at the approximate time of use.

“Polysaccharide” means a polymer of more than two saccharide moleculemonomers, which monomers can be identical or different.

“Protein stabilizer” (or “primary stabilizer”) is a chemical agent thatassists to preserve or maintain the biological structure (i.e. the threedimensional conformation) and/or biological activity of a protein (suchas a Clostridial neurotoxin, such as a botulinum toxin). Stabilizers canbe proteins or polysaccharides. Examples of protein stabilizers includehydroxyethyl starch (hetastarch), serum albumin, gelatin, collagen, aswell as a recombinant albumin, gelatin or collagen. As disclosed herein,the primary stabilizer can be a synthetic agent that would not producean immunogenic response (or produces an attenuated immune response) in asubject receiving a composition containing the primary stabilizer. Inother embodiments of the invention, the protein stabilizers may beproteins from the same species of animal that is being administered theprotein. Additional stabilizers may also be included in a pharmaceuticalcomposition. These additional or secondary stabilizers may be used aloneor in combination with primary stabilizers, such as proteins andpolysaccharides. Exemplary secondary stabilizers include, but are notlimited to non-oxidizing amino acid derivatives (such as a tryptophanderivate, such as N-acetyl-tryptophan (“NAT”)), caprylate (i.e. sodiumcaprylate), a polysorbate (i.e. P80), amino acids, and divalent metalcations such as zinc. A pharmaceutical composition can also includepreservative agents such as benzyl alcohol, benzoic acid, phenol,parabens and sorbic acid. A “recombinant stabilizer” is a “primarystabilizer” made by recombinant means, such as for example, arecombinantly made albumin (such as a recombinantly made human serumalbumin), collagen, gelatin or a cresol, such as an M-cresol.

“Stabilizing”, “stabilizes”, or “stabilization” mean that apharmaceutical active ingredient (“PAI”) retains at least 20% and up to100% of its biological activity (which can be assessed as potency or astoxicity by an in vivo LD₅₀ or ED₅₀ measure) in the presence of acompound which is stabilizing, stabilizes or which providesstabilization to the PAI. For example, upon (1) preparation of serialdilutions from a bulk or stock solution, or (2) upon reconstitution withsaline or water of a lyophilized, or vacuum dried botulinum toxincontaining pharmaceutical composition which has been stored at or belowabout −2 degrees C. for between six months and four years, or (3) for anaqueous solution botulinum toxin containing pharmaceutical compositionwhich has been stored at between about 2 degrees and about 8 degrees C.for from six months to four years, the botulinum toxin present in thereconstituted or aqueous solution pharmaceutical composition has (in thepresence of a compound which is stabilizing, stabilizes or whichprovides stabilization to the PAI) greater than about 20% and up toabout 100% of the potency or toxicity that the biologically activebotulinum toxin had prior to being incorporated into the pharmaceuticalcomposition.

“Substantially free” means present at a level of less than one percentby weight of the pharmaceutical composition.

“Therapeutic formulation” means a formulation can be used to treat andthereby alleviate a disorder or a disease, such as a disorder or adisease characterized by hyperactivity (i.e. spasticity) of a peripheralmuscle.

A pharmaceutical composition within the scope of my invention cancomprise a Clostridial toxin, such as a botulinum toxin, and arecombinant stabilizer. A pharmaceutical composition within the scope ofmy invention can also consist essentially of a botulinum toxin, and arecombinant stabilizer. Additionally, pharmaceutical composition withinthe scope of my invention can consist of a botulinum toxin, and arecombinant stabilizer.

The botulinum toxin can be present as a botulinum toxin complex (i.e. asan approximately 300 to about 900 kiloDalton complex depending upon theparticular botulinum toxin serotype) or the botulinum toxin can be ispresent as a pure or purified botulinum toxin (i.e. as the botulinumtoxin molecule of about 150 kiloDaltons). Additionally, the recombinantstabilizer can be a recombinant albumin, a recombinant collagen, arecombinant gelatin or other recombinant primary stabilizer. Thepharmaceutical composition can also comprise a secondary stabilizer,such as a metal (i.e. zinc) or NAT.

Significantly, a pharmaceutical composition within the scope of myinvention can have an enhanced potency or stability. By enhanced potencyit is meant that the potency of a first botulinum toxin pharmaceuticalcomposition is greater than the potency of a second botulinum toxinpharmaceutical composition. For example a first botulinum toxinpharmaceutical composition can comprise a recombinant primary stabilizer(such as a r-HSA) and a second botulinum toxin pharmaceuticalcomposition can comprise a non-recombinant primary stabilizer (such asHSA). Alternately, a first botulinum toxin pharmaceutical compositioncan comprise one or more secondary stabilizers (such as zinc and/or NAT)whereas a second botulinum toxin pharmaceutical composition lacks one ormore of the secondary stabilizers present in the first pharmaceuticalcomposition. Potency and relative potencies can be determined by amethod used to determine a biological activity of a botulinum toxin,such as a mouse LD₅₀ assay. Generally, greater potency means that alesser amount (i.e. fewer units) of a botulinum toxin pharmaceuticalcomposition is required to paralyze a muscle. Preferably, a firstbotulinum toxin pharmaceutical composition has at least a 5% greaterpotency (and as much as a 40% greater potency) than does a secondbotulinum toxin pharmaceutical composition.

Furthermore, a pharmaceutical composition within the scope of myinvention can have an enhanced anti-microbial activity. By enhancedanti-microbial activity it is meant that the ability of a firstbotulinum toxin pharmaceutical composition with a particular componentto inhibit the growth in a liquid solution of a particular microorganismis greater than the ability of a liquid solution of a second botulinumtoxin pharmaceutical composition without the particular componentpresent in the first botulinum toxin pharmaceutical composition toinhibit the growth of the same microorganism under the same conditions.

A preferred embodiment of my invention comprises a botulinum toxin (suchas botulinum toxin type A) and a recombinant albumin. An alternatepreferred embodiment of my invention comprises a botulinum toxin, NAT,and zinc.

Another preferred embodiment of my invention is a pharmaceuticalcomposition which can comprise (or which can consist essentially of orwhich can consist of) a botulinum toxin, a primary stabilizer, and asecondary stabilizer. The primary stabilizer can be a recombinantstabilizer (such as r-HSA) and the secondary stabilizer can be a metal,such as zinc. Other suitable secondary stabilizers can include caprylate(octanoate) and NAT.

A pharmaceutical composition within the scope of the present inventioncan also include a neurotoxin, and a polysaccharide. The polysaccharidestabilizes the neurotoxin. The pharmaceutical compositions disclosedherein can have a pH of between about 5 and 7.3 when reconstituted orupon injection. The average molecular weight of a disaccharide unit ofthe polysaccharide is preferably between about 345 D and about 2,000 D.In a more preferred embodiment, the average molecular weight of adisaccharide unit of the polysaccharide is between about 350 kD andabout 1,000 kD and in a most preferred embodiment between about 375 Dand about 700 D. Additionally, the polysaccharide can comprise at leastabout 70% amylopectin. Furthermore, the weight average molecular weightof the polysaccharide itself is between about 20 kD and about 2,500 kD.

Preferably, substantially all of the disaccharide units of thepolysaccharide comprise ether linked glucopyranose molecules. An averageof about 4 to about 10 of the hydroxyl groups present on each 10 of theglucopyranoses present in the polysaccharide are substituted, through anether linkage, with a compound of the formula (CH₂)_(n)—OH, where n canbe an integer from 1 to 10. More preferably, n is an integer between 1and 3.

In a particularly preferred embodiment, an average of about 6 to about 9of the hydroxyl groups present on each 10 of the glucopyranoses presentin the polysaccharide are substituted, through an ether linkage, with acompound of the formula (CH₂)_(n)—OH, where n can be an integer from 1to 10. And in a most preferred embodiment, an average of about 7 toabout 8 of the hydroxyl groups present on each 10 of the glucopyranosespresent in the polysaccharide are substituted, through an ether linkage,with a compound of the formula (CH₂)_(n)—OH, where n can be an integerfrom 1 to 10.

A detailed embodiment of the present invention can be a pharmaceuticalcomposition suitable for injection into a human patient, which includesa botulinum toxin, and a polysaccharide. The polysaccharide can comprisea plurality of linked glucopyranose units, each glucopyranose unithaving a plurality of hydroxyl groups, wherein an average of about 6 toabout 9 of the hydroxyl groups present on each 10 of the glucopyranosespresent in the polysaccharide are substituted, through an ether linkage,with a compound of the formula (CH₂)_(n)—OH, where n can be an integerfrom 1 to 4. The polysaccharide can be an ethyl ether substitutedpolysaccharide.

The pharmaceutical composition is suitable for administration to a humanpatent to achieve a therapeutic effect, and the neurotoxin can be one ofthe botulinum toxin serotypes A, B, C₁, D, E, F and G. In a preferredembodiment of the present invention, the pharmaceutical compositioncomprises a botulinum toxin, and a hydroxyethyl starch.

Another embodiment of the present invention can encompass apharmaceutical composition which includes a botulinum toxin, apolysaccharide, and an amino acid or a polyamino acid.

Whether the pharmaceutical composition comprises, beside the neurotoxinactive ingredient, only a polysaccharide stabilizer, only an amino acidstabilizer or both polysaccharide and amino acid stabilizers, thepharmaceutical composition retains its potency substantially unchangedfor six month, one year, two year, three year and/or four year periodswhen stored at a temperature between about −1° C. and about −15° C.Additionally, the indicated pharmaceutical compositions can have apotency or % recovery of between about 20% and about 100% uponreconstitution. Alternately or in addition, the pharmaceuticalcomposition can have a potency of between about 10 U/mg and about 30U/mg upon reconstitution, such as a potency of about 20 U/mg uponreconstitution. Significantly, the pharmaceutical composition is devoidof any albumin. Thus, the pharmaceutical composition can besubstantially free of any non-toxin complex proteins. Notably, the aminoacid can be present in an amount of between about 0.5 mg and about 1.5mg of amino acid per 100 units of botulinum toxin.

The polysaccharide can be a starch such as a hydroxyethyl starch, which,when the pharmaceutical composition comprises about 100 units of thebotulinum toxin, there can be between about 500 μg and about 700 μg ofthe hydroxyethyl starch present. Preferably, the botulinum toxin isbotulinum toxin type A, and the amino acid, when present, is selectedfrom the group consisting of lysine, glycine, histidine and arginine.

A further detailed embodiment of the present invention can be a stable,high potency, non-pyrogenic, vacuum dried botulinum toxin type Apharmaceutical composition, comprising a botulinum toxin type A complex,a polysaccharide, and, an amino acid or a polyamino acid. Thepharmaceutical composition can be albumin free, have a 1 year shelf lifeat −5 C with about 90% potency immediately upon reconstitution withsaline or water and about 80% potency 72 hours after reconstitution andstorage at 2 C. Additionally, the pharmaceutical composition can have aspecific toxicity of at least about 10⁷ U/mg upon reconstitution.

My invention also encompasses a botulinum toxin formulation whichcomprises a botulinum toxin hydroxyethyl starch (HES) glycine andprovidine.

The present invention also encompasses a lyophilized or vacuum driedpharmaceutical composition consisting essentially of a high molecularweight polysaccharide and a botulinum toxin, wherein the botulinum toxinis stabilized by the high molecular weight polysaccharide. The highmolecule weight polysaccharide can be selected from the group consistingof hydroxymethyl starch, hydroxyethyl starch, hydroxypropyl starch,hydroxybutyl starch, and hydroxypentyl starch and The botulinum toxincan be selected from the group consisting of botulinum toxin types A, B,C₁, D, E, F and G.

The polysaccharide can be present in the pharmaceutical composition inan amount of between about 1×10⁻⁹ moles of the polysaccharide per unitof a botulinum toxin to about 2×10⁻¹² moles of the polysaccharide perunit of the botulinum toxin.

The present invention also includes (a) a method for making apharmaceutical composition, comprising the step of preparing a mixtureof a botulinum toxin and a polysaccharide comprised of covalently linkedrepeating monomers, wherein the average monomer molecular weight isbetween about 350 D and about 1,000 D, and (b) a method for stabilizinga clostridial neurotoxin against denaturation or aggregation, the methodcomprising the step of contacting a clostridial neurotoxin with astabilizing composition comprising a polysaccharide. The contacting stepin this later method can comprise the step of adding to an aqueoussolution or to a lyophilized or vacuum dried powder containing aclostridial neurotoxin an effective amount of the polysaccharide.

A further aspect of the present invention is a pharmaceuticalcomposition, comprising a botulinum toxin, and a recombinantly madealbumin. This composition preferably also includes anacetyltryptophanate and salts and derivatives thereof.

An additional embodiment of the present invention is a device forinjecting a pharmaceutical composition comprising a dual chamberprefilled syringe, one chamber of which syringe contains a botulinumtoxin and the second chamber of which syringe contains a diluent orbuffer.

A further embodiment of the present invention is a method for using apharmaceutical composition, the method comprising the step of localadministration of the pharmaceutical composition to a patient to achievea therapeutic effect, wherein the pharmaceutical composition comprises abotulinum toxin, a polysaccharide and an amino acid.

Significantly, my invention also includes a pharmaceutical composition,comprising a botulinum toxin, and an amino acid. My invention alsoincludes a stable pharmaceutical composition, consisting essentially ofa botulinum toxin, and an amino acid. These pharmaceutical compositionscan be albumin free, polysaccharide free, has a 1 year shelf life at −5C with at least about 90% potency upon reconstitution with saline orwater and about 80% potency 72 hours after reconstitution and storage at2 C.

In one aspect of the invention, a method for immobilizing a mammalcomprises the step of administering a composition, which comprises atleast one botulinum toxin serotype and a polysaccharide that stabilizesthe botulinum toxin and is nonimmunogenic to the mammal. In oneembodiment, the foregoing method may be practiced by administering acomposition comprising a hetastarch.

In another embodiment of the invention, a method for immobilizing amammal, comprises the step of administering a composition to the mammal,wherein the composition comprises (i) at least one botulinum toxinserotype, and (ii) a polysaccharide, which comprises a plurality oflinked glucopyranose units that each have a plurality of hydroxyl groupspresent on each of the glucopyranoses present in the polysaccharide aresubstituted, through an ether linkage, with a compound of the formula(CH₂)_(n)—OH, where n can be an integer from 1 to 4.

In another embodiment of the invention, a method for immobilizing amammal comprises the step of administering a composition to the mammal,wherein the composition comprises a botulinum toxin, and a hydroxyethylstarch, thereby immobilizing the mammal.

In practicing the foregoing methods, the mammal may be a non-humananimal.

In another embodiment of the invention, a method for treating adomesticated animal comprises the step of administering botulinum toxinto the animal. The botulinum toxin may be administered in apharmaceutical composition. Preferably, the botulinum toxin isadministered to the animal in a composition that has a lowimmunogenicity thereby reducing, and preferably preventing, thedevelopment of immunity by the animal to the botulinum toxin. Thebotulinum toxin may be any one of the seven serotypes of botulinumtoxin, or a recombinantly synthesized botulinum toxin. The botulinumtoxin may be administered as an acute treatment, or it may beadministered chronically.

In another embodiment of the invention, a method for treating adomesticated animal comprises the step of administering at least onebotulinum toxin serotype and a polysaccharide that stabilizes thebotulinum toxin, to the domesticated animal. In one embodiment, thepolysaccharide is a hydroxyethyl starch.

In certain embodiments of the invention, the administration of theneurotoxin composition may reduce pain experienced by the animal. Inadditional embodiments, the animal receiving the neurotoxin may beinjured, and the foregoing method promotes the animal's recovery fromthe injury. One example of an injury that benefits from the invention isa leg injury, such as a broken bone. In practicing the foregoingmethods, the compositions disclosed herein may be administered to theinjured body part.

The foregoing methods may also be useful in helping a mammal recoverfrom surgery. One example of a surgical procedure is hip dysplasiasurgery. Another example is surgery for a broken bone.

The foregoing methods may be practiced utilizing a composition thatcomprises a botulinum toxin type A. In other embodiments of theinvention, the foregoing methods may be practiced with a compositionthat comprises botulinum toxin type B. In further embodiments of theinvention, the methods may be practiced with a composition thatcomprises a plurality of botulinum toxin serotypes, such as botulinumtoxin serotypes selected from the group consisting of botulinum toxinserotypes A, B, C₁, D, E, F and G. In certain embodiments of theinvention, purified botulinum toxins may be used. In other embodiments,modified botulinum toxins may be used. The compositions used in theforegoing methods may also include one or more amino acids in additionto the botulinum toxin and the polysaccharide.

In yet additional embodiments of the invention, the compositions used inthe foregoing methods may be administered intramuscularly to thepatient. In other embodiments, the compositions may be administeredsubcutaneously and/or intrathecally.

DESCRIPTION

The present invention is based upon the discovery that a stablebotulinum toxin with enhanced potency and enhanced antimicrobialactivity as well as being free of animal derived proteins, such as ablood pooled or blood fraction derived human serum albumin or gelatin,can be made with a recombinant albumin.

The present invention also encompasses a stable Clostridial toxincontaining pharmaceutical composition formulated free of any animalderived protein or donor pool albumin by incorporating a polysaccharide,an amino acid and/or a recombinant albumin into the pharmaceuticalcomposition. In particular, the present invention encompasses a stablebotulinum toxin containing pharmaceutical composition suitable foradministration to a patient for therapeutic effects made by replacingthe donor pool albumin present in known botulinum toxin containingpharmaceutical compositions with a high molecular weight polysaccharidederived from starch and/or with certain reactive amino acids.

Recombinant Albumin Botulinum Toxin Pharmaceutical Compositions and ZincContaining Botulinum Toxin Pharmaceutical Compositions

An embodiment of my invention is a botulinum toxin active ingredientpharmaceutical composition wherein, instead of human serum albumin, theprimary protein stabilizer is a recombinantly made albumin. I havesurprising found that a botulinum toxin pharmaceutical compositioncomprising a recombinant albumin has a greater potency than does abotulinum toxin pharmaceutical composition comprising the same amount(on a weight for weight basis) of a human serum albumin.

A further embodiment of my invention is a pharmaceutical compositioncomprising a botulinum toxin as the active ingredient, an albumin(either a serum albumin or a recombinantly made albumin) primary proteinstabilizer and a metal cation, such as zinc, as a secondary stabilizer.

Human serum albumin (plasma derived) is available commercially fromvarious sources, including, for example, from Bayer Corporation,pharmaceutical division, Elkhart, Ill., under the trade name Plasbumin®.Plasbumin® is known to contain albumin obtained from pooled human venousplasma as well as sodium caprylate (a fatty acid, also known asoctanoate) and acetyltryptophan (“NAT”). See e.g. the BayerPlasbumin®-20 product insert (directions for use) supplied with theproduct and as published athttp://actsysmedical.com/PDF/plasbumin20.pdf. The caprylate andacetyltryptophan in commercially available human serum albumin areapparently added by FDA requirement to stabilize the albumin duringpasteurization at 60 degrees C. for 10 hours prior to commercial sale.See e.g. Peters, T., Jr., All About Albumin Biochemistry, Genetics andMedical Applications, Academic Press (1996), pages 295 and 298.Recombinant human albumin is available from various sources, includingfor example, from Bipha Corporation of Chitose, Hokkaido, Japan, WelfideCorporation of Osaka, Japan, and from Delta Biotechnology, Nottingham,U.K., as a yeast fermentation product, under the trade name Recombumin®.

It is known to express recombinant human serum albumin (rHSA) in theyeast species Pichia pastoris. See e.g. Kobayashi K., et al., Thedevelopment of recombinant human serum albumin, Ther Apher 1998November;2(4):257-62, and; Ohtani W., et al., Physicochemical andimmunochemical properties of recombinant human serum albumin from Pichiapastoris, Anal Biochem 1998 Feb. 1;256(1):56-62. See also U.S. Pat. No.6,034,221 and European patents 330 451 and 361 991. A clear advantage ofa rHSA is that it is free of blood derived pathogens.

As set forth herein, I have discovered that a botulinum toxin containingpharmaceutical formulation can be made with a recombinant albumin (“rA”)as a primary protein stabilizer. The rA can be a recombinantly madehuman serum albumin (“rHSA”). As set forth above, it is known that arHSA can be expressed by genetically altered yeast host cells.Unexpectedly, I discovered that a pharmaceutical composition comprisinga botulinum toxin (as the active ingredient) and a recombinant albumin(as the primary protein stabilizer) has a greater potency than does apharmaceutical composition comprising a botulinum toxin (as the activeingredient) and a human serum albumin (as the primary proteinstabilizer). It was surprising to discover that a rA, such as a rHSA,can be used to stabilize a botulinum toxin, particularly in light of theknown kinetic rate effect of HSA upon botulinum toxin. While it isgenerally believed that the amino acid sequences of HSA and rHSA areidentical, there are a number of distinctions between HSA and rHSAwhich, without wishing to be bound by theory, may be responsible for theobserved surprising and unexpected greater potency of a botulinum toxinpharmaceutical composition formulated with an rHSA, as compared to abotulinum toxin pharmaceutical composition formulated with a HSA.

For example:

-   -   (1) While eukaryotic, yeast lack many intracellular processes        found in mammals. Thus HSA is made in non-glycosylated form and        (unlike rHSA) undergoes extracellular, non-enzymatic addition of        glucose. Hence, the carbohydrate moieties (substituents) HSA and        rHSA differ. The presence of, and differing, substituents can        cause conformational, and hence activity differences.    -   (2) As a blood derived product, HSA contains significant amounts        of fatty acid impurities, such as palmitic acid and stearic        acid, which fatty acids are present not at all, or in much lower        amounts, with rHSA. The fatty acids which accompany the HSA from        blood as an impurity can mask albumin binding sites, and this        binding site masking is not present with rHSA, since little or        no fatty acid impurity is present with a r-HSA.    -   (3) HSA is prepared by centrifugation (to accomplish blood        fractionation) or other separation processes, while no such        processing/separation steps are required for rHSA. Hence, the 3D        albumin molecular confirmation can differ between HSA and rHSA.    -   (4) the molecular weight distribution of HSA differs        significantly from the molecular weight distribution of rHSA, as        determined by an experiment I carried out to determine the        molecular weight distributions of HSA v rHSA. Thus, FIG. 1 shows        that commercially available HSA “A” (the upper graph A in        FIG. 1) has a significant amount of aggregate present (labeled        as “a” in FIG. 1. Aggregate is an aggregation of trimer and        higher molecular weight albumin) whereas a commercially        available rHSA “B” (the lower graph B in FIG. 1) has no        detectable aggregate albumin. In FIG. 1 “b” represents detected        dimer, “c” represents detected monomer and “d” represents        detected NAT. As shown by FIG. 1 no albumin aggregate (“a”) (nor        any NAT) was present in the rHSA examined.

Additionally, I determined by experiment (see FIG. 2) that only about90% of the human serum albumin present in a final botulinum toxinpharmaceutical composition (i.e Formulation A) was present as albuminmonomers (see graph C in FIG. 2), at the time of preparation of thepharmaceutical composition. But I also determined by experiment thatabout 95% (i.e. more than 90%) of the recombinant serum albumin presentin a botulinum toxin pharmaceutical composition was present as albuminmonomers, at the time of preparation of this pharmaceutical composition(see graph D in FIG. 2). These results therefore show that not only incommercial rHSA preparations (i.e. in the raw material of this primarystabilizer), but also in the final rHSA botulinum toxin pharmaceuticalcomposition there is significantly less albumin aggregate present, ascompared to both the corresponding a HSA raw material and the final HSAbotulinum toxin pharmaceutical composition.

-   -   (5) The isoelectric point (pI) for HSA is 5.2, but is 5.1 for        rHSA.    -   (6) HSA can contain a number of impurities: low molecular weight        impurities can include citrate (as a residue of the sodium        citrate anticoagulant used in plasma collection), fatty acids        and lipids (as an associated blood fraction component) and        various metals present due to the filters (i.e diatomaceous        earth) and blood fraction processing and separation technologies        used. High molecular substances can be present with the HSA        because commercial HSA preparations can legally contain as much        as 4% of non-albumin globulins, such as orosomucoid. Thus, FDA        requirements are that commercially available HSA need be only at        least 96% HSA, so up to 4% of non-HSA impurities can be present        with HSA. Additionally, polymeric forms of albumin (dimers,        trimers) are known to be present in commercially available lots        of HSA. See e.g. Peters, T. Jr., Chapter 7, Practical Aspects:        Albumin in the Laboratory, of All About Albumin, Biochemistry,        genetics, and medical applications, pages 298-305, Academic        Press (1996).

These six differences can be expected to result in significantdifferences in, inter alia, ligand binding, conformational stability andmolecular charge between HSA and rHSA, thereby resulting in significantdifferences between an HSA botulinum toxin pharmaceutical composition ascompared to a rHSA botulinum toxin pharmaceutical composition, the laterbeing as aspect of my invention. Thus, even though the amino acidsequences of HSA and rHSA may be identical I discovered that a botulinumtoxin pharmaceutical composition formulated with an rHSA can have anenhanced potency as compared to a botulinum toxin pharmaceuticalcomposition formulated with HSA.

Thus, as set forth an aspect of my invention encompasses replacement ofthe blood derived serum albumin in a pharmaceutical composition with arecombinant albumin (rA), such as a recombinant human serum albumin(rHSA). As explained below, preferably, the recombinant serum albumincan be present in the botulinum toxin containing pharmaceuticalformulation with acetyltryptophanate (“NAT”), as well as with P80 andcaprylate.

Commercially available human serum albumin is heated at 60° C. for tenhours as a requirement to eliminate potentially infectious agentsderived from the human blood pool. In order to prevent seriousdenaturation during this process two stabilizers are added: sodiumacetyltryptophanate (“NAT”) and sodium caprylate. With a rHSA (or otherrecombinant albumin) there is no need to add these ingredients becauseno disease risk exists and hence no heating step is required.

I have discovered that addition of sodium acetyltryptophanate (NAT) torHSA enhances the thermal stability beyond that obtained by use ofsodium caprylate alone, even when the concentration of sodium caprylateis almost doubled (from 20 mM for a HSA to 35.2 mM for a rHSA). Withoutwishing to be bound by theory, I believe that may be due to thecaprylate binding to only one site on the albumin molecule whereassodium acetyltryptophanate binds to two sites on the albumin molecule.Binding this second site appears to enhance the resistance the albuminmolecule to thermal perturbation. I can further postulate that theaddition of sodium acetyltryptophanate may in some way enhance thestability of botulinum toxin formulations, possibly by maintaining athermodynamically favorable conformation in the toxin molecule, bindingthe toxin, or by preventing denaturation of the human serum albuminitself. Therefore a preferred embodiment of my invention is apharmaceutical composition which comprises a botulinum toxin (as theactive ingredient), a rA (such as a rHSA) as a primary proteinstabilizer and a secondary stabilizer such as: N-Acetyl-tryptophan(sodium tryptophanate or NAT); sodium caprylate; another fatty acids;and divalent cations such as zinc (for example as zinc chloride). A morepreferred botulinum toxin pharmaceutical composition within the scope ofmy invention comprises a botulinum toxin, a rHSA and NAT. A verypreferred botulinum toxin pharmaceutical composition within the scope ofmy invention comprises a botulinum toxin, a rHSA, NAT, a caprylate, zincand P80 (i.e. Formulation E) because of its high potency. A mostpreferred formulation is Formulation B because this formulation has ahigher potency than the HSA formulation (i.e. Formulation A) (see FIG.3), and is more similar in composition to the already FDA approvedFormulation A (BOTOX) than is the even more potent Formulation E.

An embodiment of my invention can consist essentially of a botulinumtoxin, a rHSA and NAT, so that other excipients which do not materiallyeffect the basic characteristics of the composition, such as sodiumcaprylate, Zinc and P80, can also be present as further stabilizers ofthe botulinum toxin active ingredient, and certain trace process buffersand sodium chloride can also be present. A most preferred embodiment ofmy invention can consist of a botulinum toxin, a recombinant albumin(human or other species) and a tryptophanate, such as NAT, because Ihave discovered that such a composition provides a stabilized botulinumtoxin. A most preferred botulinum toxin pharmaceutical compositionwithin the scope of my invention can consist of a botulinum toxin, arHSA, NAT, a caprylate and P80.

Importantly, as set forth below, I have made the surprising andunexpected discovery that a stable pharmaceutical composition consistingessentially of a botulinum toxin, an albumin, and zinc (with or withoutNAT) exhibits significant and dramatic anti-microbial activity against awide variety of microbial species. This is an unexpected discoverybecause most preservatives have been shown to be incompatible withprotein drugs, including with botulinum toxin.

A most preferred pharmaceutical composition within the scope of myinvention comprises, consists essentially of or consists of a botulinumtoxin (i.e. 100 units, about 4.8-5 ng), sodium chloride (about 900 μg),a rHSA (about 500 μg), sodium caprylate (about 13 μg), NAT (about 10μg), Zinc chloride (about 4 μg) and P80 (about 0.04 μg)

As stated, sodium caprylate and/or sodium acetyltryptophanate ((NAT) canbe added to commercially available HSA to protect the HSA fromdenaturation while the HSA (required by FDA rules) is heated to 60degrees C. for 10-11 hours before the HSA can be sold.

My invention also encompasses addition of a zinc ion source to abotulinum toxin containing pharmaceutical formulation. It has beendetermined that zinc does not provide cryoprotection to a botulinumtoxin during the freeze drying step in the preparation of a freeze driedbotulinum toxin pharmaceutical composition. Prior to my invention it wasnot known that zinc can have a stabilizing function on a botulinumtoxin. It can be postulated that metals, such as divalent metal cations,may be able to enhance the stability of a freeze-dried formulation dueto various cryo-properties including the lattice structures of formedices. Extraneous metals such as copper and iron species lend themselvesto radical oxidations and are generally to be avoided. It is known thatbotulinum toxin type A toxin is dependent upon bound zinc for itsintracellular enzymatic activity. Many of the art known excipients orreaction products of these excipients, including albumin, can chelatemetals. This could lead to formation of unstable ices and/or inactivatedtoxin. By supplying ample zinc in the formulation the presence ofdesirable divalent cations is assured, the likelihood of zinc loss bythe toxin is reduced, and stability enhanced. This can be accomplishedby the addition of ZnSO₄ or ZnCl₂ to a botulinum toxin pharmaceuticalcomposition.

Polysaccharide Containing Pharmaceutical Composition

In another embodiment of my invention, I have surprisingly found that asuitable replacement for albumin can be a compound which is neitheranother protein, nor a low molecular weight, non-protein compound. Thus,I have discovered that particular high molecular weight polysaccharidescan function as neurotoxin stabilizers in a pharmaceutical composition.As set forth below, an amino acid can also, or in the alternative, beadded to the pharmaceutical composition to increase the stability anduseful storage life of the pharmaceutical composition.

The polysaccharide used in the present invention can impart stability toa neurotoxin active ingredient, such as a botulinum toxin, present inthe pharmaceutical composition by: (1) reducing adhesion (commonlyreferred to as “stickiness”) of the botulinum toxin to surfaces, such asthe surfaces of laboratory glassware, vessels, the vial in which thepharmaceutical composition is reconstituted and the inside surface ofthe syringe used to inject the pharmaceutical composition. Adhesion ofthe botulinum toxin to surfaces can lead to loss of botulinum toxin andto denaturation of retained botulinum toxin, both of which reduce thetoxicity of the botulinum toxin present in the pharmaceuticalcomposition. (2) reducing the denaturation of the botulinum toxin and/ordissociation of the botulinum toxin from other non-toxin proteinspresent in the botulinum toxin complex, which denaturation and/ordissociation activities can occur because of the low dilution of thebotulinum toxin present in the pharmaceutical composition (i.e. prior tolyophilization or vacuum drying) and in the reconstituted pharmaceuticalcomposition. (3) reducing loss of botulinum toxin (i.e. due todenaturation or dissociation from non-toxin proteins in the complex)during the considerable pH and concentration changes which take placeduring preparation, processing and reconstitution of the pharmaceuticalcomposition.

The three types of botulinum toxin stabilizations provided by thepolysaccharide conserve and preserve the botulinum toxin with it nativetoxicity prior to injection of the pharmaceutical composition.

In addition, I have discovered that the protein stabilizers disclosedherein reduce the immunogenicity of the pharmaceutical compositions, andthereby are useful in treating conditions that might benefit fromneurotoxin treatments in human and non-human subjects. Surprisingly, Ihave discovered a composition that permits administration of aneurotoxin, such as botulinum toxin, to both human and non-humansubjects without resulting in a significant immune response. Asdiscussed above, the presence of HSA in the currently available productsof botulinum toxin may preclude the ability for veterinarians toadminister botulinum toxin as a treatment for animals.

In certain embodiments of the invention, the pharmaceutical compositionsof the invention may comprise a plurality of botulinum toxin serotypes.In other words, the composition may include two or more differentbotulinum toxin serotypes. For example, a composition may includebotulinum toxin serotypes A and B. In another embodiment, a compositionmay include botulinum toxin serotypes A and E. Using a combination ofbotulinum toxin serotypes will permit caregivers to customize thecomposition to achieve a desired effect based on the condition beingtreated. In an additional embodiment of the invention, the compositionmay comprise a modified botulinum toxin. The modified botulinum toxinwill preferably inhibit the release of neurotransmitter from a neuron,but may have a greater or lower potency than the native botulinum toxin,or may have a greater or lower biological effect than the nativebotulinum toxin. Because the compositions of the invention may be usedfor relatively long-term treatment of animals, the compositions may beprovided in a relatively pure form. In one embodiment, the compositionsare of a pharmaceutical grade. In certain embodiments, the clostridialneurotoxin has a greater than 95% purity. In additional embodiments, theclostridial neurotoxin has a purity greater than 99%.

A preferred polysaccharide for use in the present composition comprisesa plurality of glucose monomers (mol wt 180) with one or moresubstituents on a majority of the glucose monomers, so that thepreferred polysaccharide has a molecular weight range of between about20 kD and about 800 kD. Surprisingly, such a polysaccharide canstabilize a neurotoxin component present in a pharmaceuticalcomposition. The present invention excludes from its scope disaccharideoligosaccharides with a weight average molecular weight of less thanabout 20 kD. The present invention also excludes from its scope cyclicpolymers such as the cyclodextrins. The latter two classes of compoundsare excluded from the scope of the present invention because the desiredstabilization characteristics of the preferred polysaccharide whilerequiring a relatively high molecular compound (i.e. molecular weight inexcess of 20 kD) do not require and indeed can make no use of the smalllipophilic cavity characteristic of the cyclodextrins, because thecyclodextrin lipophilic cavity is much smaller in size than the size ofthe neurotoxins stabilized by the preferred polysaccharides of thepresent invention. Additionally, the cyclodextrins are low molecularweight compounds comprising only about 6 to 8 glucose monomers.

The present invention also encompasses a method for stabilizingpharmaceutical compositions which contain a clostridial toxin with apolysaccharide. The stabilizing effect is achieved by bringing aclostridial toxin in contact with the polysaccharide. Examples ofsuitable polysaccharides within the scope of my invention includecertain starch and starch derivatives. As noted, the polysaccharideexhibits a stabilizing effect on the clostridial toxin. Furthermore; theeffect of the polysaccharide to stabilize a clostridial toxin can beenhanced by the addition of an amino acid.

Unexpectedly, I have discovered that 2-hydroxyethyl starch demonstratesa unique ability to stabilize the botulinum toxin present in a botulinumtoxin containing pharmaceutical composition, thereby providing apharmaceutical composition which is devoid of the potential forharboring a transmissible disease derived from human blood or bloodfraction donor pools or animal derived proteins like gelatin.

Thus, I have discovered that the particular high molecular weightpolysaccharide, hydroxyethyl starch, can stabilize the toxin duringformulation, drying, storage and reconstitution. Preferably, to furtherstabilize the protein active ingredient, an amino acid is also includedin the polysaccharide containing formulation.

The polysaccharide in the pharmaceutical composition is preferablyadmixed with the clostridial neurotoxin in an amount of about 1 μg ofpolysaccharide per unit of botulinum toxin to about 10 μg ofpolysaccharide per unit of botulinum toxin. More preferably thepolysaccharide in the pharmaceutical composition is admixed with theclostridial neurotoxin in an amount of about 4 μg of polysaccharide perunit of botulinum toxin to about 8 μg of polysaccharide per unit ofbotulinum toxin. In a most preferred embodiment, where thepolysaccharide is a hydroxyethyl starch, the hydroxyethyl starch in thepharmaceutical composition is preferably admixed with a botulinum toxintype A complex in an amount of about 5 μg of hydroxyethyl starch perunit of botulinum toxin to about 7 μg of hydroxyethyl starch per unit ofbotulinum toxin. Most preferably, the hydroxyethyl starch in thepharmaceutical composition is admixed with a botulinum toxin type Acomplex in an amount of about 6 μg of hydroxyethyl starch per unit ofbotulinum toxin. Since BOTOX® contains about 100 units of botulinumtoxin type A complex per vial and the average molecular weight ofhydroxyethyl starch is generally regarded as being between about 20 kDand about 2,500 kD, the most preferred concentration of hydroxyethylstarch is between about 1×10⁻⁹ moles per unit of botulinum toxin (M/U)to about 2×10⁻¹² moles per unit of botulinum toxin. In another preferredembodiment, for a 100 U botulinum toxin type A complex pharmaceuticalcomposition, about 600 μg of the hydroxyethyl starch and about 1 mg ofan amino acid, such as lysine, glycine, histidine or arginine isincluded in the formulation. Thus, my invention encompasses use of botha polysaccharide and an amino acid, or a polyamino acid to stabilize theneurotoxin active ingredient in the pharmaceutical composition.

Additionally, my invention also encompasses use of a suitable amino acidin a sufficient amount to stabilize the protein active ingredient in apharmaceutical composition, either in the presence of or to theexclusion of any polysaccharide being present in the formulation. Thus,I have surprisingly discovered that the inclusion of certain amino acidsinto a neurotoxin containing, pharmaceutical composition formulation canextend the useful shelf life of such a pharmaceutical composition. Thus,my invention encompasses a neurotoxin containing pharmaceuticalcomposition which includes an amino acid and the use of such apharmaceutical composition. Without wishing to be bound by theory, I canpostulate that since a neurotoxin, such as a botulinum toxin, issusceptible to oxidation, due to the presence of disulfide linkages inthe toxin complex, the inclusion of an oxidizable amino acid may act toreduce the probability that oxidizers, such as peroxides and freeradicals, will react with the neurotoxin. Thus, the likelihood that theoxidizable neurotoxin disulfide linkage will be oxidized by an oxidizer,such as peroxides and free radicals, can be reduced upon inclusion of anamino acid which can act as an oxidative sink, that is as a scavengerfor oxidizing compounds. A suitable amino acid is an amino acid which issubject to oxidation. Examples of preferred amino acids are methionine,cysteine, tryptophan and tyrosine. A particularly preferred amino acidis methionine.

A preferred embodiment of my invention can also include the use of twoor more amino acids either alone or in combination with a polysaccharideto stabilize the protein active ingredient in a pharmaceuticalcomposition. Thus, for a 100 U botulinum toxin type A containingpharmaceutical composition, about 0.5 mg of lysine and about 0.5 mg ofglycine can be used, either with or without between about 500 μg andabout 700 μg of hetastarch.

Thus, as set forth above, my invention encompasses a protein containing,pharmaceutical composition which includes a polysaccharide. Thepolysaccharide acts to stabilize the protein active ingredient in thepharmaceutical composition. Additionally, my invention also includes aprotein containing, pharmaceutical composition which includes apolysaccharide and an amino acid. Surprisingly, I have discovered thatthe inclusion of certain amino acids into a neurotoxin containing,pharmaceutical composition formulation which includes a carbohydrate canextend the useful shelf life of such a pharmaceutical composition. Thus,my invention encompasses a neurotoxin containing pharmaceuticalcomposition which includes both a polysaccharide and an amino acid andthe use of such a pharmaceutical composition. Furthermore, my inventionalso encompasses use of an amino acid without any polysaccharide beingpresent in the protein active ingredient pharmaceutical composition.

It is known that protein containing pharmaceutical compositions whichalso contain sugars, polysaccharides and/or carbohydrates (referred tohereafter as “reactive compounds”) are inherently unstable due to thefact that a protein and one of the three indicated reactive compoundscan undergo the well-described Maillard reaction. Extensive, largelyfruitless, research has been carried out to try and reduce the incidenceor prevalence of this (for example) protein-polysaccharide Maillardreaction, by reduction of moisture or by the use of non-reducing sugarsin the formulation. My discovery is based upon the observation thatinclusion of a high concentration of a highly reactive amino acidencourages the Maillard reaction to take place between the stabilizingpolysaccharide and the added amino acid. By providing an abundant aminesource for the carbohydrate to react with, the probability of theprotein drug (i.e. botulinum toxin active ingredient) becoming involvedin the Maillard is reduced, thereby reducing this degradation pathway ofthe protein active ingredient and in this manner thereby stabilizing theprotein active ingredient in the pharmaceutical composition.

Preferably, any compound containing a primary or secondary amine can beused for this purpose. Most preferred are amino acids, such as lysine,glycine, arginine. Polyamino acids, such as polylysine are alsosuitable. Cationic amino acids such as lysine may undergo ionicattraction, binding acidic proteins (e.g., botulinum toxins) and shieldthe active protein from contact with sugars. Polylysine, in addition tobeing larger and therefore more likely to act as a shield, provides theadditional advantage of being antibacterial.

Another aspect of my invention is to pre-react the sugar and amino acidcomponents to exhaust Maillard reaction potential before adding theactive protein component (botulinum toxin) to the sugar and amino acidformulation ingredients, thereby substantially limiting the activeprotein's exposure to Maillard reactions.

Thus, my invention encompasses a pharmaceutical composition containingand the use of an amino acids and polyamino acids as Maillard reactioninhibitors in protein (i.e. botulinum toxin) drug formulations whichcontain starches, sugars and/or polysaccharides.

The invention embodies formulations of active proteins (e.g., botulinumtoxin) in combination with a stabilizing starch, sugar, orpolysaccharide or combination of these, and an amino acid such aslysine.

Significantly, I have discovered that hydroxyethyl starch does notundergo or undergoes a much attenuated rate or level of Maillardreactions with a protein, such as a botulinum toxin, when hydroxyethylstarch is compared to other polysaccharides or carbohydrates.Additionally, I have discovered that inclusion of an amino acid enhancesthe preservation effect of hydroxyethyl starch, possibly by acting as acompetitive inhibitor, that is by competing with the toxin for Maillardreaction reactive sugars. For this purpose, amino acids such as lysine,glycine, arginine and histidine are preferred amino acids. Polyaminoacids, such as polylysine, which exhibit the desired competitiveinhibition behavior can also be used. Notably, the specified amino andpoly amino acids can also exhibit antimicrobial properties, providingtherefore the added benefit of reducing bacterial contamination in thepharmaceutical composition.

Reducing sugars, such as glucose and glucose polymers, undergo Maillardreaction with proteins. Even sugar alcohols like mannitol can react,albeit sometimes through contaminants or degradation products. Thereforea polysaccharide can stabilize the toxin for a period of time only tochemically react later, thereby causing reduced storage stability. It isobvious that the choice of polysaccharide is critical. I have discoveredthat the rate of hydroxyethyl starch participation in the Maillardreaction is very low. Additionally, I have found that hydroxyethylcellulose, although structurally very similar to hydroxyethyl starch, isunsuitable to use as a stabilizer, since I have found that hydroxyethylcellulose can rapidly react in a model system with lysine. This not onlymeans that hydroxyethyl starch has an obvious advantage over other sugar(i.e. polysaccharide) stabilizers, but that even excipients similar tohydroxyethyl starch, such as hydroxyethyl cellulose, can be unsuitableto use as stabilizers of a protein active ingredient in a pharmaceuticalformulation.

As noted, hydroxyethyl starch, can participate to at least some extent,in Maillard reactions. Thus, and as set forth above, a polysaccharidealone may not be sufficient to provide optimal stabilization of thetoxin. Thus, I discovered the advantages of inclusion of an amino acidto act as a competitive inhibitor. Without wishing to be bound bytheory, the hypothesis is that by providing another amine source, inhigh concentrations compared to the toxin, the probability of theMaillard reaction occurring with the toxin is reduced, therebystabilizing the toxin. Any amino acid can be used however lysine beinghighly reactive and is a preferred amino acid.

Although recombinant serum albumin is preferred over animal-derivedserum albumin, it is a further aspect of my invention to provide acomposition that may comprise a serum albumin obtained from the speciesof animal intended to be treated. For example, if a horse were toreceive an injection of a clostridial neurotoxin, such as botulinumtoxin, it may be desirable to utilize a composition comprising theneurotoxin and an equine serum albumin as a stabilizer. Similarly, if acow were to receive an injection of a clostridial neurotoxin, thecomposition containing the neurotoxin may include bovine serum albuminas a stabilizer. This reasoning will similarly apply to other animalspecies, including primate serum albumin for non-human primates, porcineserum albumin for pigs, canine serum albumin for dogs, feline serumalbumin for cats, and murine serum albumin for rodents. Otherspecies-specific serum albumins are provided in the compositions of theinvention.

One composition of the invention may comprise botulinum toxin type A,and serum albumin from horses, dogs, cats, rabbits, pigs or rodents.

Another composition of the invention may comprise botulinum toxin typeB, C₁, D, E, F, or G; and serum albumin from non-human primates, cows,horses, pigs, dogs, cats or rodents.

As persons skilled in the art will readily appreciate, although theserum derived albumins may have some of the shortcoming discussedherein, they may still find some use in veterinary care.

My invention also encompasses addition of a preservative, either in thediluent or formulation itself, to allow extended storage. A preferredpreservative is preserved saline containing benzyl alcohol.

A liquid formulation can be advantageous. A single-step presentation(e.g., pre-filled syringe) or a product configuration that the userperceives as a single-step presentation (e.g., dual-chambered syringe)would provide convenience by eliminating the reconstitution step.Freeze-drying is a complicated, expensive and difficult process. Liquidformulations are often easier and cheaper to produce. On the other handliquid formulations are dynamic systems and therefore more susceptibleto excipient interaction, fast reactions, bacterial growth, andoxidation than freeze-dried formulations. A compatible preservativemight be needed. Anti-oxidants such as methionine might also be usefulas scavengers especially if surfactants are used to reduce adsorption asmany of these compounds contain or produce peroxides. Any of thestabilizing excipients which can be used in a freeze-dried formulation(e.g., hydroxyethyl starch or an amino acid such, lysine) might beadapted to use in a liquid formulation to assist in reducing adsorptionand stabilize the toxin. Suspensions similar to those developed forinsulin are also good candidates. Additionally, stabilizing botulinumtoxin in a liquid vehicle might require a low pH vehicle as the toxin isreported to be labile above pH 7. This acidity could produce burning andstinging upon injection. A binary syringe could be employed.

Inclusion of a co-dispensed buffer, sufficient to raise the pH tophysiologic levels, would alleviate injection discomfort of a low pHwhile maintaining the toxin at a low pH during storage. Anotherdual-chambered syringe option would include diluent and lyophilizedmaterial segregated in separate chamber, only mixing upon use. Thisoption provides the advantages of a liquid formulation without theadditional resources and time.

Thus, the botulinum toxin can be prepared at low pH to be co-dispensedwith a buffer which raises the pH to at or near physiological pH at thetime of administration. The two chamber or binary syringe can have inthe first chamber (next to the plunger) a liquid formulation of abotulinum toxin with a pH between 3 to 6 (i.e. at pH 4.0). The secondchamber (next to the needle tip) can contain a suitable buffer, such asphosphate buffered saline at a higher pH (i.e. pH 7.0). Alternately, thefirst chamber can contain a saline diluent and the second chamber cancontain a freeze dried or lyophilized neurotoxin formulation. The twochambers can be joined in such a way and the buffering componentsselected in such a way that the solutions mix at or near the needle,thereby delivering the final solution at a physiological pH. Suitabletwo chamber syringes to use as pre-filled syringes for the purposes setforth herein can be obtained from Vetter Pharma-Fertigung of Yardley,Pa.

There are distinct advantages to formulating botulinum toxin at a lowpH. The toxin has a low isoelectric point (pI) and formulating proteinsnear their pI is a known way to stabilize a protein. Additionally, thetoxin is used at a very low concentration making surface adsorption aproblem. Use of a low pH solution can suppress ionization of toxin siteslikely to interact with surfaces. The syringe and plunger materials arematerials which reduce surface adsorption by the toxin. Suitable suchmaterials are polypropylene.

As discussed herein, the neurotoxin may be prepared and purified usingtechniques well-known in the art. The purified toxin may subsequently bediluted in a stabilizer such as a polysaccharide (e.g., hetastarch), ora recombinant serum albumin, or a serum albumin of the species of animalreceiving the neurotoxin. It is preferred that the stabilizer preventsor reduces denaturation of the toxin, and produces no, or minimal,immunogenic responses in the animal that will receive the toxin.Aliquots of the diluted toxin are then lyophilized using conventionalprocedures.

The lyophilized neurotoxin may be reconstituted before administering theneurotoxin to a subject by adding water, saline, or any buffer solutionto the lyophilized neurotoxin. In certain embodiments, sodium freebuffers may be preferred to help reduce denaturation of the neurotoxin.

The pharmaceutical compositions of the invention can be administeredusing conventional modes of administration. In preferred embodiments ofthe invention, the compositions are administered intramuscularly orsubcutaneously to the subject. In other embodiments, the compositions ofthe invention may be administered intrathecally. In addition, thecompositions of the invention may be administered with one or moreanalgesic or anesthetic agents.

The most effective mode of administration and dosage regimen for thecompositions of this invention depends upon the type, severity, andcourse of the condition being treated, the animal's health and responseto treatment, and the judgment of the treating doctor. Accordingly, themethods and dosages of the compositions should be tailored to theindividual subject.

By way of example, and not by way of limitation, it may be preferred toadminister the composition of the invention intramuscularly to reducemuscle spasms associated with a specific condition. Spasms in veterinaryanimals can be caused by congenital defects (Hickford et al., J SmallAnim Pract 1998 39(6):281-5), hip dysplasia (Bowen, Am J Vet Res 197435(5):661-8), inflammation (Anderson and Harvey, J Vet Dent 199310(1):6-8) multiple sclerosis, stroke, tumors, traumas, or neurologicdegenerative diseases. Administering the compositions disclosed hereinto animals may be particularly effective in treating specific conditionssuch as “teary eyes” or “tail flick” in animals. Injecting botulinumtoxin periodically (e.g., every three to six months) in the same areasmay allow for long term, indefinite relief of spastic symptoms in theseanimals without the unwanted development of resistance to the toxin.

Similarly, the compositions of the invention may be administeredintramuscularly to immobilize an injured animal. Injuries that result infractures and tendon rupture require the limb associated with the siteof injury to be completely immobilized so as to prevent reinjury.Although the site is placed in a cast, often the animals will reinjurethemselves with ongoing activity. The only way to completely immobilizethe animal is general anesthesia, which cannot be employed for long termuses. In addition, immobilization of the injured body part with a cast,for example, may cause bone malformation and with improper functionalrecovery (Hawthorne et al., J Am Anim Hosp Assoc 1999 35(2):135-146).

Intramuscular injection of the compositions of the invention can resultin selective and reversible immobilization of the animal, or body partsthereof. For example, the compositions of the invention may beadministered locally to one or more muscle groups of an injured bodypart. In other cases, it may be necessary to perform whole bodyimmobilization of the musculature involved in whole body movements (limbmuscles and abdominal muscles) without impinging the respiratory systemor muscles involved in food intake. In such a scenario, the animal willnot be able to willfully move any parts of the body involved inambulatory movements, so physical restraints may not be necessary. Otherfunctions required to maintain the overall health of the animal wouldpreferably be still intact, so therefore a normal functioning animal iskept at a “temporary paralytic” state. Furthermore, depending on thetype of neurotoxin in the composition administered to the animal, therate of recovery may be controlled. For example, a compositioncontaining botulinum toxin type E may be administered if the caregiverdecides that a relatively shorter time of paralysis is needed to promoterecovery. In addition, because the effects of the neurotoxin wear offgradually, the activity of the immobilized body parts can be regained ata rate which is most desirable to achieve proper healing and recovery.

The compositions of the invention may also be injected into smoothmuscles (as compared to striated muscles) to treat colonic, bladder,esophageal, or gastrointestinal dysfunction, including, but not limitedto achalasia, anal fissure, hyperactive sphincter of oddi. Theadministration of the compositions may reduce or prevent unfavorablesystemic consequences from treatment with drugs that do not specificallyact on the organ of interest.

Compositions containing botulinum toxin may be administeredintramuscularly, intrathecally, or subcutaneously to relieve painexperienced by the animal. These treatments are also restricted to thesite of injection and have minimal side effects compared to currentsystemic approaches of treating these pain syndromes with pain relievingdrugs.

Pain may be difficult to determine in an animal; however, animals mayexhibit one or more behaviors indicative of the animal experiencingpain. For example, the animal may cease its normal activities, or it mayfavor a potentially injured limb. The animal may stop eating, may whine,may have an increased respiration rate, or heart rate, may have anabnormal temperature, or may appear restless. In addition, animalsexperience intestinal discomfort, such as colic, and may experience oneor more of the following symptoms in addition to the symptoms identifiedabove, paw the ground, may sweat, may be restless, may appear bloated,and experience muscle tremors.

Relief from pain by practicing the methods of the invention may bedetermined by observing the reduction in the number of symptoms that theanimal is exhibiting. One or more of the symptoms may be reduced.

Injection of botulinum toxin to multiple muscles, such as leg muscles,may be effective to cause a potent, prolonged, yet reversibleimmobilization of wild, non-domesticated animals. This procedure can beused for medical evaluation of the patient, various local or minormedical or dental procedures, or for transport. In practicing thesemethods, it may be desirable to also inject either before, or at thesame time, a tranquilizer to provide immediate effects ofimmobilization.

As indicated above, dosages of the neurotoxin, such as botulinum toxin,in the compositions may vary. In one embodiment, the compositionscontain a therapeutically effective amount of neurotoxin, for example,between about 1 U and about 500 U of botulinum toxin type A. Preferablythe amounts are between about 10 U and about 300 U. More preferably theamount is between about 20 U and 250 U, such about 50 U to 200 U, or 70U.

Alternatively, botulinum toxin, such as botulinum toxin type A, can beadministered in amounts between about 10⁻³ U/kg and about 60 U/kg toalleviate pain experienced by a mammal. Preferably, the botulinum toxinused is administered in an amount of between about 10⁻² U/kg and about50 U/kg. More preferably, the botulinum toxin is administered in anamount of between about 10⁻¹ U/kg and about 40 U/kg. Most preferably,the botulinum toxin is administered in an amount of between about 1 U/kgand about 30 U/kg. In a particularly preferred embodiment of the presentdisclosed methods, the botulinum toxin is administered in an amount ofbetween about 1 U/kg and about 20 U/kg.

Compositions containing other serotypes of botulinum toxin may containdifferent dosages of the botulinum toxin. For example, botulinum toxintype B may be provided in a composition at a greater dose than acomposition containing botulinum toxin type A. In one embodiment of theinvention, botulinum toxin type B may be administered in an amountbetween about 1 U/kg and 150 U/kg. Botulinum toxin type B may also beadministered in amounts of up to 20,000 U (mouse units, as describedabove). In another embodiment of the invention, botulinum toxin types Eor F may be administered at concentrations between about 0.1 U/kg and150 U/kg. In addition, in compositions containing more than one type ofbotulinum toxin, each type of botulinum toxin can be provided in arelatively smaller dose than the dose typically used for a singlebotulinum toxin serotype. The combination of botulinum toxin serotypesmay then provide a suitable degree and duration of paralysis without anincrease in diffusion of the neurotoxins (e.g. see U.S. Pat. No.6,087,327).

EXAMPLES

The following examples set forth specific embodiments of the presentinvention and are not intended to limit the scope of the invention.

Example 1 Human Serum Albumin Botulinum Toxin Pharmaceutical Composition(Formulation A)

A botulinum toxin type A complex can be obtained from a culture of theHall strain of Clostridium botulinum grown in a medium containing N-Zamine and yeast extract. The botulinum toxin type A complex is purifiedfrom the culture solution by a series of acid precipitations to acrystalline complex consisting of the active high molecular weight toxinprotein and an associated hemagglutinin protein. The crystalline complexis then re-dissolved in a solution containing saline and albumin andsterile filtered (0.2 microns) prior to vacuum-drying. The vacuum driedcomposition can be reconstituted with sterile, non-preserved salineprior to injection. Each vial of vacuum dried composition can containabout 100 units (U) of Clostridium botulinum toxin type A complex, 0.5milligrams of human serum albumin and 0.9 milligrams of sodium chloridein a sterile, vacuum-dried form without a preservative (Formulation A).

Example 2 Recombinant Human Serum Albumin Botulinum Toxin PharmaceuticalComposition (Formulation B)

A botulinum toxin type A complex was obtained as set forth in Example 1and the same pharmaceutical composition made, except that instead ofHSA, an rHSA was used in the formulation.

Example 3 Potency Differences Between Human Serum Albumin BotulinumToxin Pharmaceutical Compositions and Recombinant Human Serum AlbuminBotulinum Toxin Pharmaceutical Compositions

Upon lyophilization and after less than one week of storage at −5degrees C. (i.e. at T₀) the vacuum dried pharmaceutical compositions ofExamples 1 and 2 (i.e.

Formulations A and B) were reconstituted with sterile normal salinewithout a preservative (0.9% sodium chloride injection) and theirrespective potencies determined by the known mouse LD50 assay. Othersamples of the lyophilized botulinum toxin type A complex Formulations Aand B (as well as samples of the Formulations C-F described below) werestored at −5 degrees C. for six months and then reconstituted with thesterile normal saline without a preservative (0.9% sodium chlorideinjection) and their respective potencies were again determined (i.e. atT₆) using the mouse LD50 assay.

Table 1 sets forth the constituents of the six different botulinum toxinpharmaceutical compositions made. Formulations B, C, E and F in Table 1contain a rHSA. Formulations A and D in Table 1 contain an HSA. As shownby FIG. 3, it was found that:

-   -   (a) the potency of Formulation A was 85 at T₀ and 72 at T₆.    -   (b) the potency of Formulation B was 96 at T₀ and 95 at T₆. This        experiment therefore showed that Formulation B was 13% more        potent at T₀ and 32% more potent at T₆ than was Formulation A.        Thus, it was found that surprisingly the rHSA formulation (B)        was more potent than was the HSA formulation (A).    -   (c) the potency of a Formulation B to which 10 micrograms of NAT        were added per 100 units of toxin (to thereby make a        Formulation C) was 100 at T₀ and 97 at T₆. This experiment        therefore showed that Formulation C was 18% more potent at T₀        and 35% more potent at T₆ than was Formulation A. Thus, it was        found that surprisingly, the addition of NAT to the rHSA        formulation (B) further increased the potency of Formulation B        as compared to the HSA formulation, Formulation A. This was a        surprising discovery since Formulation A already contained the        same amount of NAT which was used to make Formulation C. Hence,        it was surprisingly discovered that NAT provided an increase to        the potency of the toxin with rHSA which was not provided by NAT        to the HSA toxin formulation.    -   (d) the potency of Formulation A (HSA toxin) to which 4        micrograms of zinc chloride was added (to thereby make a        Formulation D) increased to 107 at T₀ and 94 at T₆. This        experiment therefore showed that surprisingly the addition of        zinc increased the potency of Formulation D as compared to        Formulation A. Formulation D was 26% more potent at T₀ than was        Formulation A and Formulation D was 31% more potent at T₆ than        was Formulation A. Thus, the addition of zinc significantly        increased the potency of the HSA toxin formulation.    -   (e) the potency of Formulation C to which of 4 micrograms of        zinc chloride was added (to thereby make a Formulation E)        increased the potencies to 116 T₀ and to 99 at T₆. This        experiment therefore showed that the addition of zinc increased        the potency of Formulation E as compared to Formulation C (16%        increase at T₀ and 2% increase at T₆). Thus, surprisingly the        addition of zinc by itself increased the potency of the r-HSA        formulation.

Notably, the increase in potency of Formulation E as compared toFormulation A was 36% at T₀ and 38% at T₆. Thus, it was surprisinglydiscovered that the addition of zinc to the rHSA formulation provided atoxin which was substantially more potent than was the HSA toxin withoutzinc formulation (A). Hence, Formulation E is a most preferredpharmaceutical composition.

A further Formulation F was made by adding 4 micrograms of zinc chlorideto Formulation B. TABLE 1 Botulinum Toxin (Type A Complex)Pharmaceutical Compositions Formu- Toxin NaCl Albumin Octan- NAT ZnCl₂P80 lation (units) (ug) (ug) oate (ug) (ug) (ug) (ug) A 100 900 500 7 100 0 HSA B 100 900 500 13 0 0 0.04 r-HSA C 100 900 500 13 10 0 0.04 r-HSAD 100 900 500 7 10 4 0 HSA E 100 900 500 13 10 4 0.04 r-HSA F 100 900500 13 0 4 0.04 r-HSA

The increased potencies of certain botulinum toxin formulations, as setforth by the experiment above, can be directly linked to an enhancedstability. In other words, a greater relative potency of one formulationwith regard to another formulation can mean that one formulation hasmore botulinum toxin molecules which retain their biological activity(i.e. are stabilized).

Thus, my invention encompasses addition of a zinc ion source to abotulinum toxin containing pharmaceutical (HSA or rHSA) formulation tothereby obtain a more potent toxin formulation. As shown by FormulationsD, E and F (vacuum dried before reconstitution) in FIG. 3, the presenceof zinc in the formulations provided an enhanced potency at T₀, ascompared to the non-zinc containing formulations (A, B and C) at T₀.

A further experiment was carried out whereby the potencies of twoversions of Formulation E were determined at T₀. It was found thatvacuum dried and liquid versions (the later not vacuum or freeze dried))of Formulation E had statistically identical potencies (116 vs 115) atT₀. This later experiment showed therefore that the zinc was notproviding a cryo-protectant effect to the botulinum toxin but that thezinc present was providing a enhanced potency at T₀ to the zinccontaining formulations. Hence, it was determined that zinc does notprovide cryoprotection to a botulinum toxin during the freeze dryingstep in the preparation of a freeze dried botulinum toxin pharmaceuticalcomposition. Prior to my invention it was not known that zinc can have astabilizing function on a botulinum toxin. It can be postulated thatmetals, such as divalent metal cations, may be able to enhance thestability of a freeze-dried formulation due to various cryo-propertiesincluding the lattice structures of formed ices. Extraneous metals suchas copper and iron species lend themselves to radical oxidations and aregenerally to be avoided. It is known that botulinum toxin type A toxinis dependent upon bound zinc for it's intracellular enzymatic activity.Many of the art known excipients or reaction products of theseexcipients, including albumin, can chelate metals. This could lead toformation of unstable ices and/or inactivated toxin. By supplying amplezinc in the formulation the presence of desirable divalent cations isassured, the likelihood of zinc loss by the toxin is reduced, andstability enhanced. This can be accomplished by the addition of ZnSO₄ orZnCl₂ to a botulinum toxin pharmaceutical composition.

Example 4 Zinc Containing Botulinum Toxin Pharmaceutical Compositionswith Enhanced Anti-Microbial Activity

It was determined that the zinc containing formulations D-F showedanti-microbial activity, as compared to the non-zinc containingformulations A-C, against the two microorganisms Escherichia coli andPseudomonas aeruginosa. Formulations A to F were assessed byreconstituting samples of each of the six lyophilized formulations withnon-preserved saline (0.9% NaCl for injection) (1-mL/100 unit vial)followed by storage at room temperature. Separate 100 unit vials of eachof the six reconstituted formulations were then inoculated to containapproximately 110-140 one hundred colony-forming units (CFU) permilliliter of the microorganisms Escherichia coli (ATCC 8739) andPseudomonas aeruginosa (ATCC 9027). Solutions were vortexed and werestored at room temperature (22.5±2.5° C.) for 5 days. At 24 hours, 48hours, and 5 days after inoculation the samples were assayed todetermine the numbers of viable CFU per milliliter. Data is presented inlogarithmic reductions (−) or logarithmic increases (+) in Table 2.NR=No Recovery (<10 CFU/mL) TABLE 2 Antimicrobial Activity of SixDifferent Botulinum Toxin Pharmaceutical Compositions Formu- P.aeruginosa E. coli lation Time 140 CFU/mL 110 CFU/mL A 24 hrs +1.08+1.99 48 hrs +2.80 +3.28 5 days +4.17 +4.21 B 24 hrs +0.86 +0.68 48 hrs+2.54 +2.06 5 days +3.97 +3.98 C 24 hrs +0.56 +0.75 48 hrs +1.48 +1.64 5days +3.95 +3.76 D 24 hrs −0.10 −0.34 48 hrs 0.00 −0.56 5 days +1.36 NRE 24 hrs −0.30 −0.34 48 hrs +0.08 NR 5 days +2.54 NR F 24 hrs +0.59+0.26 48 hrs −0.10 NR 5 days +1.69 NR

The results of this experiment showed that the zinc containingFormulations D, E, F had significantly less microbial growth as comparedthe non-zinc containing formulations A, B, C, against the two indicatedmicroorganisms. Prior to my invention it was unknown that zinc canprovide an enhanced antimicrobial activity to a pharmaceutical activeingredient which is an enzyme, such as a botulinum toxin. Typically,proteins, and especially enzymes, do not retain biological activity inthe presence of an anti-microbial agent.

Example 5 Botulinum Toxin Pharmaceutical Composition Containing2-Hydroxyethyl Starch

Botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations were prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin was replaced by either500 μg or 600 μg of hetastarch. It was determined that full potency wasmaintained upon preparation of the hetastarch containing formulations.Thus, with both hetastarch containing formulations, the potency of thealbumin-free, hetastarch containing composition, as measured at the timeof reconstitution of the lyophilized, 100 U (±20 U) botulinum toxin typeA complex, was from 96 to 128 units. Three separate hetastarch,botulinum toxin type A complex pharmaceutical compositions had potencymeasurements, at the time of reconstitution, of, respectively, 105, 111and 128 units. Potency was measured using the standard administration tomice toxin potency assay.

Example 6 Botulinum Toxin Pharmaceutical Composition Containing Glycine

Botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations was prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin was replaced by either500 μg or 600 μg of hetastarch. In addition 1 mg of glycine was added tothe formulation. A lyophilized, hetastarch plus glycine, albumin-free,100 U botulinum toxin type A complex, pharmaceutical composition wasthen stored for seven months at −5° C. At the end of this seven monthperiod the potency of this hetastarch plus glycine toxin formulation wasdetermined, using the mouse administration assay, to be essentiallyunchanged (i.e. potency differed by less than 5% from the originalpotency).

Example 7 Botulinum Toxin Pharmaceutical Composition Containing Lysine

100 U botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations are prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin was replaced by 600 μgof hetastarch. In addition 1 mg of lysine is added to the formulation. Alyophilized, hetastarch plus lysine, albumin-free, 100 U botulinum toxintype A complex, pharmaceutical composition is then stored for one yearat −5° C. At the end of this one year period the potency of thishetastarch plus lysine, toxin formulation is determined, using the mouseadministration assay, to be essentially unchanged (i.e. potency differsby less than 5% from the original potency).

Example 8 Botulinum Toxin Pharmaceutical Composition ContainingHistidine

100 U botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations are prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin was replaced by 600 μgof hetastarch. In addition 1 mg of histidine is added to theformulation. A lyophilized, hetastarch plus histidine, albumin-free, 100U botulinum toxin type A complex, pharmaceutical composition is thenstored for one year at −5° C. At the end of this one year period thepotency of this hetastarch plus histidine, toxin formulation isdetermined, using the mouse administration assay, to be essentiallyunchanged (i.e. potency differs by less than 5% from the originalpotency).

Example 9 Botulinum Toxin Pharmaceutical Composition Containing Arginine

100 U botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations are prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin was replaced by 600 μgof hetastarch. In addition 1 mg of arginine is added to the formulation.A lyophilized, hetastarch plus arginine, albumin-free, 100 U botulinumtoxin type A complex, pharmaceutical composition is then stored for oneyear at −5° C. At the end of this one year period the potency of thishetastarch plus arginine, toxin formulation is determined, using themouse administration assay, to be essentially unchanged (i.e. potencydiffers by less than 5% from the original potency).

Example 10 Botulinum Toxin Pharmaceutical Composition Containing anAmino Acid

100 U botulinum toxin type A purified neurotoxin complex pharmaceuticalformulations can be prepared in the same manner set forth in Example 1above, except that the 0.5 milligrams of albumin can be replaced byabout 1 mg of an amino acid such as lysine, glycine, histidine orarginine. Thus a lyophilized, polysaccharide free, albumin free, glycinecontaining, botulinum toxin type A complex, pharmaceutical compositioncan be prepared and stored for at least one year −5° C., and at the endof this period can have a potency of which is essentially unchanged(i.e. potency can differ by less than 5% from the original potency).

Example 11 Use of a Botulinum Toxin Pharmaceutical Composition

A 48 year old male is diagnosed with a spastic muscle condition, such ascervical dystonia. Between about 10⁻³ U/kg and about 35 U/kg of abotulinum toxin type A pharmaceutical composition containing 600 μg ofhetastarch and 1 mg of an amino acid, such as lysine, is injectedintramuscularly into the patient. Within 1-7 days the symptoms of thespastic muscle condition are alleviated and alleviation of the symptomspersists for at least from about 2 months to about 6 months.

Example 12 Use of a Botulinum Toxin Pharmaceutical Composition to TreatEquine Colic

A two year old thoroughbred is brought into a veterinary clinic forevaluation of a recent onset of poor feeding, fussiness, and beingrider-unfriendly. Blood chemistry indicates that the horse has metabolicdisturbances of low glucose, hyperkalemia, and low blood count. Urinaryexcretion indicative of dehydration is noticed. The horse is diagnosedwith colic. A composition containing between about 10⁻³ U/kg and about35 U/kg of botulinum toxin A and 600 μg of hetastarch is intrathecallyand transabdominally injected at several sites on three separate officevisits. After three months, all signs of colic disappear and the horseis reintroduced into the racing circuit.

Example 13 Use of a Botulinum Toxin Pharmaceutical Composition to Treata Canine

An owner of a 3 year-old German shepherd comes to a clinic concernedabout a week history of limping and general lethargy of her dog. Anx-ray is performed and a diagnosis of hip dysplasia is made. The animalundergoes hip replacement surgery. The dog's hips are cast, andbotulinum toxin A injection is suggested to provide furtherimmobilization of the rear legs and hips. Multiple injections of acomposition comprising about 20 U/kg of botulinum toxin type A and 600μg of hetastarch are given to the animal. The dog recuperates for about4 weeks before removal of the cast. After removal of the cast, the dogcontinues to rest. A little after 8 weeks, the dog begins to regain somefunction of his legs. After 4 months, the dog has regained enoughfunction to begin regular walking. By 6 months, the dog resumes normalactivities.

A year after the hip replacement, the dog is lethargic, does not eat,and appears to be in distress. The dog is brought to a veterinarian fordiagnosis. Except for low blood glucose, all other blood chemistryvalues appear normal. A barium scan of the upper GI finds narrowing ofthe lower esophageal sphincter, resulting in a megaesophagus. Diagnosisof achalasia is made, and botulinum toxin injection is suggested. Aninjection of a composition containing botulinum toxin type A andhetastarch into the lower esophageal sphincter muscles is performedusing fiberoptic guidance. Importantly, one week later, a second bariumscan is performed, revealing a complete opening of the sphincter, andindicating that the dog has not developed immunity to the toxin from hisearlier surgery. The owner notices cessation of vomiting and normalfeeding habits.

Example 14 Use of a Botulinum Toxin Pharmaceutical Composition toImmobilize an Animal

A 4 year old angus bull is transported under general anesthesia to alarge animal veterinary clinic facility for an evaluation of a fracturedtibia resulting from a fight with another bull. X-ray evaluation reveals3 fracture points restricted to the right, rear tibia without fracturesto the fibula. The shin is plaster-casted, and it is recommended thatthe bull be completely immobilized to allow the leg to heal properly. Acomposition containing about 40 U/kg of botulinum toxin A and 600 μg ofhetastarch is injected in several large muscle groups, including all thelimb front and rear limb muscles. No injection is made to the abdominalrectus, cervical spinal, or facial muscles. The bull is completelyimmobilized but retains full functional control over food intake. Aftersix months and two complete panels of injections, the limb heals enoughto allow weight-bearing, but restricted movements within its own bullpen. After three more months the bull is allowed to be with other bullsto resume more physical activities.

Example 15 Use of a Botulinum Toxin Composition to Treat Canine MuscleSpasms

A 10 year old Yorkshire terrier is brought into a clinic for anevaluation of muscle spasms confined to the right half of the body. ACAT scan of the head reveals a large, intraparenchymal mass in the leftbrain, and biopsy reveals a grade II astrocytoma. Euthanasia is proposedby the veterinarian.

However, the owner still wants to spend the last few weeks of qualitytime with her dog and does not want the animal to suffer any pain thatmay result from the muscle spasms. Botulinum toxin injection issuggested. Injections are made in spastic musculature on the right side.The injections successfully abolish all spastic activities. The doglives the remaining two weeks without spasms and according to the owner,happy and “appeared to be rather healthy”.

Example 16 Use of a Botulinum Toxin Pharmaceutical Composition to TreatFounder

A four-year-old Welsh mare has been habitually overfed a rich diet ofalfalfa hay. The owner finds the pony hobbling in obvious pain andunable to walk normally. Upon examination the veterinarian diagnoses theproblem as founder and recommends a strict diet and regular exerciseuntil the animal's symptoms subside.

However, neither the owner nor the veterinarian can convince the pony towalk more than a few steps at a time. If normal exercise is not quicklyresumed the animal will be permanently crippled. A compositioncontaining approximately of 100 U botulinum toxin type A and 500 μg HSAis injected into the hooves enabling the pony to apply pressure to thepreviously painful area. Within two weeks the pony regains its normalgait and resumes pulling a small cart containing the owner's children.

Example 17 Multiple Component Botulinum Toxin Formulations

As set forth briefly in the Definitions sections supra under thedefinition of “Pharmaceutical Composition” a multiple (i.e. two or more)component system for the making of a final formulation can provide thebenefit of allowing incorporation of ingredients which are notsufficiently compatible for long-term shelf storage with the firstcomponent of the two component system or which for other reasons it isnot desirable to include with the first component of the pharmaceuticalcomposition. In this manner what I refer to as adaptive neurotoxin (i.ebotulinum toxin) formulations can be prepared.

rHSA and HSA can require secondary stabilizers such asN-Acetyltryptophan, sodium caprylate, fatty acids, surfactants anddivalent cations for optimum long-term stability. Studies utilizingprobe formulations indicate that some of these secondary stabilizers mayinduce enhanced potency or stability on neurotoxin (i.e botulinum toxin)formulations. This example sets forth a way to add the appropriateconcentration of these ingredients to obtain the desired effect. One wayto accomplish this is to include the ingredient in the base formulation.Another is to add it to a base formulation prior to use. As set forthherein, Zinc, for example, may enhance the potency or liquid stabilitywhen added to an existing neurotoxin (i.e botulinum toxin) formulationnot containing zinc. Other beneficial stabilizing ingredients canlikewise be added in this manner.

A limitation of the current Botox® formulation is related to the usefullength of the product. Currently the recommended (for sterility reasons)life after reconstitution of Botox® is about four hours. This is due tothe fact that the product contains no preservative. The diluent, saline,also contains no preservative. Studies indicate that incorporation ofsome preservatives can degrade the toxin over a long storage time (i.e.up to 2 years) of the vacuum dried product. However, utilization of adiluent containing a preservative would expose the toxin to degradationprocesses for a much shorter time while still providing preservativeefficacy, that is the time of use, and thereby allow incorporation of apreservative.

A problem related to removal of protein stabilizers is clinicalperformance. Studies with hetastarch stabilized formulations indicatedifferences in performance (safety profile) possibly related todiffusion characteristics of the HES when compared to HSA. Otherstabilizers (such as povidone) which perform similarly to HSA have thusfar proven incompatible during storage, thereby limiting theirusefulness. Incorporating them into a diluent or reconstitution vehiclewould eliminate long-term exposure of the toxin to the incompatiblespecies during which such degradation could occur. Therefore a HES orsaline vacuum-dried formulation could be reconstituted in a vehiclecontaining a carrier, such as povidone, providing a shelf-stable productwith the desired clinical performance.

Buffer salts or physiological pH conditions also may cause degradationduring long-term storage. Enhanced storage stability may only beachievable by providing a suitable pH environment not suitable forinjection (burning/stinging), such as low pH. A two-part system wouldovercome these limitations. A low pH shelf-stable formulation could bediluted or reconstituted using a buffer to overwhelm the capacity of thefirst composition, thereby providing a comfortable physiologic pH forinjection.

Other advantages allow for changing the vehicle depending on use; i.e.,the carrier could be selected according to the desired clinicaldiffusion characteristics. For example, toxin vacuum-dried in SWI,reconstituted with HES for one indication (cosmetic) and HSA for another(therapeutic). Stabilizing the toxin in SWFI, then reconstituting withsaline (to obtain isotonicity) is another formulation option.

The final formulation might also be adapted to provide for patientsallergic to a particular ingredient (a collagen vehicle substituted fora patient allergic to gelatin, for example). Otherwise, the base toxinformulation could be reconstituted with different albumins derived froma particular species for use in veterinary applications (equine serumalbumin for use in horses, bovine serum albumin for use in cattle, asexamples).

The basis of the invention is a formulation combined with adaptive,specialized vehicles/diluents to obtain the desired characteristics. Theproduct can consist of three (or more) components; e.g., a viralcontaining a stable solid toxin and two pre-filled syringes containingdifferently formulated reconstitution vehicles.

Examples of three-component systems:

Version I (Solid/Liquid):

-   -   1. Toxin vacuum dried in NaCl    -   2. Reconstitution vehicle containing HSA or rHA    -   3. Second reconstitution vehicle containing HES        (recon with rHA to obtain Botox safety profile/HES to obtain        modulated safety profile)        Version II (Solid/Liquid):    -   1. Toxin vacuum dried in NaCl    -   2. Reconstitution vehicle containing Povidone    -   3. Second reconstitution vehicle containing HES        (reconstitute with Povidone to obtain Botox safety profile/HES        to obtain modulated safety profile)        Version III (Solid/Liquid):    -   1. Toxin vacuum dried in SWFI (sterile water for injection)    -   2. Reconstitution vehicle containing Povidone    -   3. Second reconstitution vehicle containing HES        (reconstitute with Povidone to obtain Botox safety profile/HES        to obtain modulated safety profile)        Version IV (Liquid/Liquid):    -   1. Toxin liquid stabilized with a buffer at pH 4    -   2. Diluent liquid buffered to pH 7 containing HSA    -   3. Second diluent liquid buffered to pH 7 containing HES        (dilute with HSA diluent to obtain Botox safety profile/HES to        obtain modulated safety profile)        Version VI (Solid/Liquid):    -   1. Toxin vacuum dried in SWFI (sterile water for injection)    -   2. Reconstitution vehicle containing HSA or rHA and preservative    -   3. Second reconstitution vehicle containing HES and preservative        (reconstitute with HSA/rHA to obtain Botox safety profile/HES to        obtain modulated safety profile; preservative is compatible with        toxin to retain potency during specified time of use (e.g., 48        hours))

A pharmaceutical composition according to the invention disclosed hereinhas many advantages, including the following:

-   -   1. the pharmaceutical composition can be prepared free of any        blood product, such as albumin and therefore free of any blood        product infectious element such as a prion.    -   2. the pharmaceutical composition has stability and high %        recovery of toxin potency comparable to or superior to that        achieved with currently available pharmaceutical compositions.

Accordingly, the pharmaceutical compositions disclosed herein havereduced immunogenicity and therefore enable medical caregivers to treatanimals with a reduced risk that the animal will develop an immuneresponse to the administered composition.

Various publications and/or references have been cited herein, thecontents of which, in their entireties, are incorporated herein byreference.

Although the present invention has been described in detail with regardto certain preferred methods, other embodiments, versions, andmodifications within the scope of the present invention are possible.For example, a wide variety of stabilizing polysaccharides and aminoacids are within the scope of the present invention.

Accordingly, the spirit and scope of the following claims should not belimited to the descriptions of the preferred embodiments set forthabove.

1-18. (canceled)
 19. A pharmaceutical composition, comprising (a) abotulinum toxin; (b) N-acetyl-tryptophan (NAT); (c) zinc; (d) caprylate;(e) recombinant human serum albumin (rHSA), and; (f) polysorbate 80(P80), wherein the pharmaceutical composition exhibits both an enhancedantimicrobial activity and an enhanced potency.
 20. The pharmaceuticalcomposition of claim 19, wherein the botulinum toxin is present as abotulinum toxin complex.
 21. The pharmaceutical composition of claim 19,wherein the botulinum toxin is present as a pure botulinum toxin. 22.The pharmaceutical composition of claim 19, wherein the botulinum toxinis selected from a group consisting of a botulinum toxin serotype A, B,C₁, D, E, F and G.
 23. The pharmaceutical composition of claim 22,wherein the botulinum toxin is botulinum toxin type A.
 24. Thepharmaceutical composition of claim 19, wherein the zinc is zincchloride.
 25. The pharmaceutical composition of claim 19, wherein thecaprylate is a sodium caprylate.
 26. The pharmaceutical composition ofclaim 19 further comprising sodium chloride.
 27. The pharmaceuticalcomposition of claim 26, wherein for each 100 units of the botulinumtoxin there is present in the pharmaceutical composition about 10micrograms of NAT, about 4 micrograms of zinc, about 13 micrograms ofcaprylate, about 500 micrograms of rHSA, about 0.04 micrograms of P80and about 900 micrograms of sodium chloride.
 28. A pharmaceuticalcomposition, comprising (a) a botulinum toxin; (b) N-acetyl-tryptophan(NAT); (c) zinc; (d) caprylate (e) recombinant human serum albumin(rHSA), and (f) polysorbate 80 (P80), wherein the pharmaceuticalcomposition exhibits both an enhanced antimicrobial activity and anenhanced potency and the botulinum toxin is botulinum toxin type A. 29.A pharmaceutical composition, comprising (a) a botulinum toxin; (b) atryptophan, and; (c) a recombinant albumin (rA), wherein thepharmaceutical composition exhibits an enhanced potency.
 30. Thepharmaceutical composition of claim 29, wherein the botulinum toxin ispresent as a botulinum toxin complex.
 31. The pharmaceutical compositionof claim 29 wherein the botulinum toxin is present as a pure botulinumtoxin.
 32. The pharmaceutical composition of claim 29, wherein thebotulinum toxin is selected from a group consisting of a botulinum toxinserotype A, B, C₁, D, E, F and G.
 33. The pharmaceutical composition ofclaim 29, wherein the botulinum toxin is botulinum toxin type A.
 34. Thepharmaceutical composition of claim 29, further comprising zinc.
 35. Thepharmaceutical composition of claim 34, further comprising a caprylate.36. The pharmaceutical composition of claim 35 further comprising sodiumchloride.
 37. The pharmaceutical composition of claim 36, wherein foreach 100 units of the botulinum toxin there is 10 micrograms of thetryptophan NAT, 4 micrograms of zinc, 13 micrograms of caprylate, 500micrograms of rA, 0.04 micrograms of P80 and 900 micrograms of sodiumchloride.
 38. A pharmaceutical composition, comprising (a) a botulinumtoxin; (b) N-acetyl-tryptophan (NAT); (c) zinc; (d) caprylate (e)recombinant albumin (rA), and (f) polysorbate 80 (P80), wherein thepharmaceutical composition exhibits an enhanced potency and thebotulinum toxin is botulinum toxin type A.